By: HISTORY.com Editors Causes of World War II and Hitler's Rise to Power Outbreak of World War II (1939) World War II in the West: German Expansion in Western Europe (1940-41) Hitler vs. Stalin: Operation Barbarossa (1941-42) World War II in the Pacific (1941-43) Toward Allied Victory in World War II (1943-45) World War II Ends (1945) Black Soldiers in World War II: Fighting Abroad and at Home World War II Casualties and Legacy Photo Galleries World War II, the largest and deadliest conflict in human history, involved more than 50 nations and was fought on land, sea and air in nearly every part of the world. Also known as the Second World War, it was caused in part by the economic crisis of the Great Depression and by unresolved political tensions following the end of World War I. The war began when Nazi Germany invaded Poland in 1939 and raged across the globe until 1945, when Japan surrendered to the United States after atomic bombs were dropped on Hiroshima and Nagasaki. By the end of World War II, an estimated 60 to 80 million people had died, including up to 55 million civilians, and numerous cities in Europe and Asia were reduced to rubble. Among the people killed were 6 million Jews murdered in Nazi concentration camps as part of Hitler’s diabolical “Final Solution,” now known as the Holocaust. The legacy of the war included the creation of the United Nations as a peacekeeping force and geopolitical rivalries that resulted in the Cold War. World War II with Tom Hanks “World War II with Tom Hanks” is the definitive retelling for a new generation: a sweeping, deeply human portrait of how the modern world was forged in global war. Causes of World War II and Hitler's Rise to Power Treaty of Versailles : The harsh terms of the 1919 treaty caused political and social resentment throughout Germany. Treaty of Versailles : The harsh terms of the 1919 treaty caused political and social resentment throughout Germany. The Great Depression : Economies in the United States, Europe, Latin America and worldwide were devastated. The Great Depression : Economies in the United States, Europe, Latin America and worldwide were devastated. Rise of Nationalism : The 1930s saw the rise of nationalist political movements, including Germany’s Nazi Party, Italy’s fascist movement and militarism in Japan and elsewhere. Rise of Nationalism : The 1930s saw the rise of nationalist political movements, including Germany’s Nazi Party, Italy’s fascist movement and militarism in Japan and elsewhere. The devastation of the Great War (as World War I was known at the time) had greatly destabilized Europe, and in many respects, World War II grew out of issues left unresolved by that earlier conflict. The Great Depression of 1929 to 1939 and the economic ruin it caused worldwide exacerbated those unresolved issues. In particular, political and economic instability in Germany during the Weimar Republic and lingering resentment over the harsh terms imposed by the Treaty of Versailles fueled the rise to power of Adolf Hitler and the National Socialist German Workers’ Party, abbreviated as NSDAP in German and the Nazi Party in English. After becoming chancellor of Germany in 1933, Hitler swiftly consolidated power, anointing himself Führer (supreme leader) in 1934. Obsessed with the idea of the superiority of the “pure” German race, which he called “Aryan,” Hitler believed that war was the only way to gain the necessary “Lebensraum,” or living space, for the German race to expand. As early as 1923, in his memoir and propaganda tract "Mein Kampf" (My Struggle), Adolf Hitler had predicted a general European war that would result in "the extermination of the Jewish race in Germany." In the mid-1930s, Hitler secretly began the rearmament of Germany, a violation of the Versailles Treaty. It was the first of several violations of the treaty, which Germans found oppressive and debilitating. Outbreak of World War II (1939) Germany Occupies Austria and Czechoslovakia : In open violation of the Treaty of Versailles, Germany annexed the two nations to gain territory. Germany Occupies Austria and Czechoslovakia : In open violation of the Treaty of Versailles, Germany annexed the two nations to gain territory. The German-Soviet Nonaggression Pact : Hitler and Joseph Stalin agreed in August 1939 to not attack one another, giving Hitler an opening to invade Poland in September 1939 with Soviet support. The German-Soviet Nonaggression Pact : Hitler and Joseph Stalin agreed in August 1939 to not attack one another, giving Hitler an opening to invade Poland in September 1939 with Soviet support. German U-boat Attacks : While attacks on land slowed after Poland and the Baltic regions were occupied, German submarines began sinking merchant ships in the Atlantic. German U-boat Attacks : While attacks on land slowed after Poland and the Baltic regions were occupied, German submarines began sinking merchant ships in the Atlantic. After signing alliances with Italy and Japan against the Soviet Union, Hitler sent troops to occupy Austria in 1938 and the following year annexed Czechoslovakia . Hitler’s open aggression went unchecked, as the United States and Soviet Union were concentrated on internal politics at the time, and neither France nor Britain (the two other nations most devastated by the Great War) was eager for another confrontation. In late August 1939, Hitler and Soviet leader Joseph Stalin signed the German-Soviet Nonaggression Pact, which sparked a frenzy of worry in London and Paris. Hitler had long planned an invasion of Poland, a nation to which Great Britain and France had guaranteed military support if it were attacked by Germany. The pact with Stalin meant that Hitler would not face a war on two fronts once he invaded Poland, and would have Soviet assistance in conquering and dividing the nation itself. On September 1, 1939, Hitler invaded Poland from the west; two days later, France and Britain declared war on Germany, beginning World War II. On September 17, Soviet troops invaded Poland from the east. Under attack from both sides, Poland fell quickly, and by early 1940, Germany and the Soviet Union had divided control over the nation, according to a secret protocol appended to the Nonaggression Pact. Stalin’s forces then moved to occupy the Baltic States (Estonia, Latvia and Lithuania) and defeated a resistant Finland in the Russo-Finnish (or Winter) War. During the months following the invasion of Poland, the lack of action on the part of Germany and the Allies in the west led to talk in the news media of a “phony war.” At sea, however, the British and German navies faced off in heated battle, and lethal German U-boat submarines struck at merchant shipping bound for Britain, sinking more than 100 vessels in the first four months of World War II. World War II in the West: German Expansion in Western Europe (1940-41) German Blitzkrieg Stunned European Forces : Coordinated land and air attacks in 1940 quickly overwhelmed forces in France, Belgium and the Netherlands. German Blitzkrieg Stunned European Forces : Coordinated land and air attacks in 1940 quickly overwhelmed forces in France, Belgium and the Netherlands. France Falls Quickly : After breaking through the Maginot Line, French resistance collapsed and Germany occupied Paris. France Falls Quickly : After breaking through the Maginot Line, French resistance collapsed and Germany occupied Paris. The Blitz Devastates London : Luftwaffe bombing raids inflict heavy damage and civilian casualties in London and other major cities from 1940-41. The Blitz Devastates London : Luftwaffe bombing raids inflict heavy damage and civilian casualties in London and other major cities from 1940-41. On April 9, 1940, Germany simultaneously invaded Norway and occupied Denmark, and the war began in earnest. On May 10, German forces swept through Belgium and the Netherlands in what became known as “ blitzkrieg ,” or lightning war. German forces used fast-moving Panzer tanks, Luftwaffe (German Air Force) air support and artillery vehicles in a coordinated fashion to quickly overwhelm their targets. Three days later, Hitler’s troops crossed the Meuse River and struck French forces at Sedan, located at the northern end of the Maginot Line , an elaborate chain of fortifications constructed after World War I and considered an impenetrable defensive barrier. The German blitzkrieg, however, quickly broke through the line with their tanks and planes, rendering the Maginot Line useless. The British Expeditionary Force (BEF) was evacuated by sea from Dunkirk back to England in late May, leaving behind valuable tanks, vehicles and equipment. Farther south, French forces mounted a doomed resistance. With France on the verge of collapse, Italy’s fascist dictator Benito Mussolini —who had formed the Pact of Steel alliance with Hitler in 1939—declared war on France and Britain on June 10, 1940. On June 14, German forces entered Paris. A new government formed by Marshal Philippe Pétain (France’s hero of World War I) requested an armistice two nights later. France was subsequently divided into two zones, one under German military occupation and the other under Pétain's government, installed at Vichy, France. Hitler then turned his attention to Britain, which had the defensive advantage of being separated from the European continent by the English Channel. To pave the way for an amphibious invasion (dubbed Operation Sea Lion), German planes bombed Britain extensively beginning in September 1940 until May 1941, known as the Blitz , including night raids on London and other industrial centers that caused heavy civilian casualties and damage. The Royal Air Force (RAF) eventually defeated the Luftwaffe (German Air Force) in the Battle of Britain, and Hitler postponed his plans to invade. With Britain’s defensive resources pushed to the limit, Prime Minister Winston Churchill began receiving crucial aid from the United States under the Lend-Lease Act , passed by Congress in early 1941. The Lend-Lease Act was a compromise that allowed the United States to provide aid to England while avoiding full involvement in World War II. Hitler vs. Stalin: Operation Barbarossa (1941-42) The German Lebensraum : Hitler believed his Aryan master race needed land for expansion and the vast Soviet Union was considered a prime target. The German Lebensraum : Hitler believed his Aryan master race needed land for expansion and the vast Soviet Union was considered a prime target. Operation Barbarossa : The surprise 1941 invasion of the Soviet Union initially succeeded, but was slowed by Soviet resistance and the onset of winter. Operation Barbarossa : The surprise 1941 invasion of the Soviet Union initially succeeded, but was slowed by Soviet resistance and the onset of winter. Battle of Stalingrad : In some of the most hellish fighting of World War II, Soviet forces defeated invading German forces. Battle of Stalingrad : In some of the most hellish fighting of World War II, Soviet forces defeated invading German forces. By early 1941, Hungary, Romania and Bulgaria had joined the Axis powers of Germany, Italy and Japan, and Axis troops overran Yugoslavia and Greece that April. Hitler’s conquest of the Balkans was a precursor to his real objective: an invasion of the Soviet Union, whose vast territory would give the German master race the “Lebensraum” it needed. The other half of Hitler’s strategy was the extermination of the Jews from throughout German-occupied Europe. Plans for the “Final Solution” were introduced around the time of the German invasion of the Soviet Union, and over the next three years, more than 4 million Jews would perish in the death camps established in occupied Poland. On June 22, 1941, Hitler ordered the invasion of the Soviet Union on the war’s Eastern Front, codenamed Operation Barbarossa . Though Soviet tanks and aircraft greatly outnumbered the Germans’, Russian aviation technology was largely obsolete, and the impact of the surprise invasion helped the Germans get within 200 miles of Moscow by September. Arguments between Hitler and his commanders delayed the next German advance until October, when it was stalled by a Soviet counteroffensive and the onset of harsh winter weather. A Soviet counteroffensive launched in November 1942 ended the bloody Battle of Stalingrad , which had seen some of the fiercest combat of World War II. The approach of another winter, along with dwindling food and medical supplies, spelled the end for German troops there, and the last of them surrendered on February 2, 1943. Play our World War II Events Quiz Test your knowledge of World War II events in this timed quiz. World War II in the Pacific (1941-43) The Path to Pearl Harbor How did things get so bad between the US and Japan in the lead up to WWII? It all comes down to power and resources. With Britain facing Germany in Europe, the United States was the only nation capable of combating Japanese aggression, which by late 1941 included an expansion of its ongoing war with China and the seizure of European colonial holdings in the Far East. On December 7, 1941, 360 Japanese aircraft attacked the major U.S. naval base at Pearl Harbor in Hawaii, taking the Americans completely by surprise and claiming the lives of more than 2,300 troops. The attack on Pearl Harbor served to unify American public opinion in favor of entering World War II, and on December 8, Congress declared war on Japan with only one dissenting vote. Germany and the other Axis Powers promptly declared war on the United States. After a long string of Japanese victories, the U.S. Pacific Fleet won the Battle of Midway in June 1942, which proved to be a turning point in the war. On Guadalcanal , one of the southern Solomon Islands, the Allies also had success against Japanese forces in a series of battles from August 1942 to February 1943, helping turn the tide further in the Pacific. In mid-1943, naval forces of the Allied powers—primarily the United States, Great Britain, China and the Soviet Union—began an aggressive counterattack against Japan, involving a series of amphibious assaults on key Japanese-held islands in the Pacific. This “island-hopping” strategy proved successful, and Allied forces gradually moved closer to their ultimate goal of invading mainland Japan. Toward Allied Victory in World War II (1943-45) Germany’s Eastern Offensive Failed : Following their disastrous invasion of the Soviet Union, Axis powers in the east were destroyed. Germany’s Eastern Offensive Failed : Following their disastrous invasion of the Soviet Union, Axis powers in the east were destroyed. D-Day Invasion : Allied forces established a crucial beachhead at Normandy, paving the way for a land assault on beleaguered German forces. D-Day Invasion : Allied forces established a crucial beachhead at Normandy, paving the way for a land assault on beleaguered German forces. Battle of the Bulge : An eventual Allied victory after a lengthy winter offensive forced Germany into a retreat. Battle of the Bulge : An eventual Allied victory after a lengthy winter offensive forced Germany into a retreat. In North Africa, British and American forces had defeated the Italians and Germans by 1943. An Allied invasion of Sicily and Italy followed, and Mussolini’s government fell in July 1943, though Allied fighting against the Germans in Italy would continue until 1945. On the Eastern Front, a Soviet counteroffensive launched in November 1942 ended the bloody Battle of Stalingrad, which had seen some of the fiercest combat of World War II. The approach of winter, along with dwindling food and medical supplies, spelled the end for German troops there, and the last of them surrendered on February 2, 1943. Battle of Stalingrad In July 1942, the Nazi Army bombs the Soviet city of Stalingrad, launching one of the bloodiest battles in history. On June 6, 1944–celebrated as “D-Day” –the Allies began a massive invasion of Europe, landing 156,000 British, Canadian and American soldiers on the beaches of Normandy, France. In response, Hitler poured all the remaining strength of his army into Western Europe, ensuring Germany’s defeat in the east. Soviet troops soon advanced into Poland, Czechoslovakia, Hungary and Romania, while Hitler gathered his forces to drive the Americans and British back from Germany in the Battle of the Bulge (December 1944-January 1945), the last major German offensive of the war. An intensive aerial bombardment in February 1945 preceded the Allied land invasion of Germany, and by the time Germany formally surrendered on May 8, Soviet forces had occupied much of the country. Hitler was already dead, having died by suicide on April 30 in his Berlin bunker. World War II Ends (1945) Potsdam Conference : The victorious Allies in Europe discussed peace terms with Germany. Potsdam Conference : The victorious Allies in Europe discussed peace terms with Germany. Germany Is Divided : The Allied powers divided a defeated Germany into four occupation zones. Germany Is Divided : The Allied powers divided a defeated Germany into four occupation zones. Japanese Resistance : Fierce fighting continued in the Pacific theater until the United States dropped two atomic bombs on Japan, forcing a Japanese surrender and ending World War II. Japanese Resistance : Fierce fighting continued in the Pacific theater until the United States dropped two atomic bombs on Japan, forcing a Japanese surrender and ending World War II. At the Potsdam Conference of July-August 1945, U.S. President Harry S. Truman (who had taken office after Franklin D. Roosevelt’s death in April), Churchill and Stalin discussed the ongoing war with Japan as well as the peace settlement with Germany. Post-war Germany would be divided into four occupation zones, to be controlled by the Soviet Union, Britain, the United States and France. On the divisive matter of Eastern Europe’s future, Churchill and Truman acquiesced to Stalin, as they needed Soviet cooperation in the war against Japan. Heavy casualties sustained in the campaigns at Iwo Jima (February 1945) and Okinawa (April-June 1945), and fears of an even costlier land invasion of Japan, led Truman to authorize the use of a new and devastating weapon. Developed during a top-secret operation code-named the Manhattan Project , the atomic bomb was unleashed on the Japanese cities of Hiroshima and Nagasaki in early August. On August 15, the Japanese government issued a statement declaring it would accept the terms of the Potsdam Declaration, and on September 2, U.S. General Douglas MacArthur accepted Japan’s formal surrender aboard the USS Missouri in Tokyo Bay. The Hiroshima Bombing Didn’t Just End WWII—It Kick-Started the Cold War The colossal power of the atomic bomb drove the world’s two leading superpowers into a new confrontation. The colossal power of the atomic bomb drove the world’s two leading superpowers into a new confrontation. Black Soldiers in World War II: Fighting Abroad and at Home A tank and crew from the 761st Tank Battalion in front of the Prince Albert Memorial in Coburg, Germany, 1945. A tank and crew from the 761st Tank Battalion in front of the Prince Albert Memorial in Coburg, Germany, 1945. Military and Support Roles : More than 1 million U.S. Black Americans served in World War II in both combat and support roles. Military and Support Roles : More than 1 million U.S. Black Americans served in World War II in both combat and support roles. Segregated Units : Black and white service members operated in racially segregated units until President Harry Truman signed a 1948 executive order integrating the U.S. military. Segregated Units : Black and white service members operated in racially segregated units until President Harry Truman signed a 1948 executive order integrating the U.S. military. Black Combat Units : The all-Black Tuskegee Airmen, 761st Tank Battalion and 92nd Infantry Division achieved renown for their fighting abilities. Black Combat Units : The all-Black Tuskegee Airmen, 761st Tank Battalion and 92nd Infantry Division achieved renown for their fighting abilities. World War II exposed a glaring paradox within the United States Armed Forces. Although more than 1 million African Americans served in the war to defeat Nazism and fascism, they did so in segregated units. The same discriminatory Jim Crow policies that were rampant in American society were reinforced by the U.S. military. Black servicemen rarely saw combat and were largely relegated to labor and supply units that were commanded by white officers. There were several Black units that proved essential in helping to win World War II, with the Tuskegee Airmen being among the most celebrated. But the Red Ball Express, the truck convoy of mostly Black drivers was responsible for delivering essential goods to General George S. Patton ’s troops on the front lines in France. The all-Black 761st Tank Battalion fought in the Battle of the Bulge, and the 92nd Infantry Division fought in fierce ground battles in Italy. Despite their role in defeating fascism, the fight for equality continued for Black soldiers after World War II ended. They remained in segregated units and lower-ranking positions, well into the Korean War , a few years after President Truman signed an executive order to desegregate the U.S. military in 1948. How the Nazis Were Inspired by Jim Crow To craft legal discrimination, the Third Reich studied the United States. To craft legal discrimination, the Third Reich studied the United States. World War II Casualties and Legacy Devastating Loss of Life : Of the 60 to 80 million deaths during World War II, most were civilians, including 6 million victims of the Holocaust. Devastating Loss of Life : Of the 60 to 80 million deaths during World War II, most were civilians, including 6 million victims of the Holocaust.

Nuremberg Trials : German military and political officials faced charges of war crimes and crimes against humanity. Nuremberg Trials : German military and political officials faced charges of war crimes and crimes against humanity. The Cold War : As communism was established in Eastern Europe, the Soviet Union and the United States became rival superpowers. The Cold War : As communism was established in Eastern Europe, the Soviet Union and the United States became rival superpowers. World War II proved to be the deadliest international conflict in history, taking the lives of 60 to 80 million people, including 6 million Jews who died at the hands of the Nazis during the Holocaust . Civilians made up an estimated 50-55 million deaths from the war, while military deaths comprised 21 to 25 million of those lost during the war. Millions more were injured, and still more lost their homes and property. From 1945 to 1946, the International Military Tribunal convened in Nuremberg, Germany, to prosecute high-ranking political, military and economic leaders for war crimes, crimes against humanity and crimes against peace. Known as the Nuremberg Trials, these proceedings established important legal precedents. How a Psychiatrist at Nuremberg Got Inside the Nazi Mind American Douglas Kelley decided the German leaders were all sane. American Douglas Kelley decided the German leaders were all sane. The legacy of the war included the spread of communism from the Soviet Union into Eastern Europe as well as its eventual triumph in China, and the global shift in power from Europe to two rival superpowers—the United States and the Soviet Union—that would soon face off against each other in the Cold War . After the successful use of atomic bombs against Japan, the United States continued to develop nuclear weapons. The Soviets tested their own atomic bomb in 1949, triggering a nuclear arms race —a race that soon included China, France, the United Kingdom, Pakistan, India and North Korea. Profound social and political changes also came about in the years following World War II: more women were accepted into the workforce ; demands for equal rights from Black Americans and other minorities were addressed; technologies advanced in health care, transportation and energy; and the United Nations and other nongovernmental organizations were established as international peacekeeping institutions. Photo Galleries On December 7, 1941, the Japanese military launched a surprise attack on the U.S. Naval base at Pearl Harbor. The attack killed 2,403 service members and wounded 1,178 more, and sank or destroyed six U.S. ships. Japanese torpedo bombers flew just 50 feet above the water as they fired at the U.S. ships in the harbor, while other planes strafed the decks with bullets and dropped bombs. A sailor stands among wrecked airplanes at Ford Island Naval Air Station as he watches the explosion of the USS Shaw. Smoke rises from the burning buildings on Ford Island, Pearl Harbor. A sailor runs for cover past flaming wreckage hit by dive bombers that had already blasted Pearl Harbor and Hickam Field at the Kaneohe Bay Naval Station. Smoke pouring from sinking battleship USS California (center); capsized bulk of USS Oklahoma visible (at right). The USS Arizona explodes after a Japanese attack. Blasted in the Dec. 7 Pearl Harbor raid, the USS Arizona rests in the mud, guns jutting out and its tower leaning precariously. A cork life preserver with a white canvas cover from battleship USS Arizona after the Japanese attack on Pearl Harbor. After a year of training, Japan’s six carriers and 420 planes sailed 3,500 miles from the Kurile Islands to strike near Oahu. This December 7 file image shows an aerial view of battleships in the U.S. Pacific Fleet consumed by the flames at Pearl Harbor after 360 Japanese warplanes made a massive surprise attack. A damaged B-17C Flying Fortress bomber sits on the tarmac near Hangar Number 5 at Hickam Field, after the Japanese attack on Pearl Harbor, Hawaii. In a flooded dry dock, the destroyer Cassin lies partly submerged and leaning against another destroyer, the Downes. The battleship Pennsylvania, shown in the rear, remained relatively undamaged. Two servicemen sit on the wreckage of a bomber, surrounded by dirt and sandbags, on Hickam Field after the Japanese attack on Pearl Harbor, Honolulu, Hawaii. The wreckage of a Japanese torpedo plane shot down during the surprise attack on December 7 being salvaged from the bottom of Pearl Harbor, Pearl Harbor, Hawaii, January 7, 1942. Military personnel pay their respects beside the mass grave of 15 officers and others killed in the bombing attack at Pearl Harbor on December 7, 1941. A U.S. flag is draped over the coffins. May 1942: Sailors at Kaneohe, Hawaii, lay leis on comrades’ graves from the Dec. 7 attack, with Ulupa’u Crater in the background. A woman operating a hand drill while working on a “Vengeance” dive bomber, in Nashville, Tennessee. A woman works on an airplane motor at the North American Aviation, Inc., plant in Inglewood, California. A woman worker tightens the cowling for one of the motors of a B-25 bomber being assembled in the engine department of the Inglewood plant. A group of women, with no previous industrial experience, are reconditioning used spark plugs in a converted Buick plant to produce airplane engines in Melrose Park, Illinois, 1942. Two women workers are shown capping and inspecting tubing which goes into the manufacture of the “Vengeance” (A-31) dive bomber made at Vultee’s Nashville division, Tennessee. A riveter sitting on huge piece of machinery during WWII, perfectly illustrating the Rosie the Riveter-type, at Lockheed Aircraft Corp. Women workers at the Douglas Aircraft Company install fixtures and assemblies to a tail fuselage section of a B-17F bomber, better known as the “Flying Fortress.” Women at work on C-47 Douglas cargo transport at the Douglas Aircraft Company in Long Beach, California A group of Black women welders kneel in coveralls and hold tools as they prepare to work on SS ‘George Washington Carver,’ Richmond, California, 1943. Marcella Hart, mother of three children, works as a wiper at the at the Chicago & Northwestern Railroad roundhouse in Clinton, Iowa. She wears the iconic red bandana in “Rosie the Riveter” fashion. A woman prepares for jobs in the Army or in industry in a camouflage class at New York University. Irma Lee McElroy, formerly an office worker, took a position at the Naval Air Base in Corpus Christi, Texas during the war. Here she is seen painting the American insignia on airplane wings. Mary Saverick stitches harnesses at the Pioneer Parachute Company Mills, in Manchester, Connecticut. Eloise J. Ellis was appointed by civil service to be senior supervisor in the Assembly and Repairs Department at the Naval Air Base in Corpus Christi, Texas. Two Navy wives, Eva Herzberg and Elve Burnham, entered war work after their husbands joined the service. In a Glenview, Illinois, they assemble bands for blood transfusion bottles at Baxter Laboratories. On June 6, 1944, more than 156,000 American, British and Canadian troops stormed 50 miles of Normandy’s fiercely defended beaches in northern France. Allied leaders Franklin D. Roosevelt and Winston Churchill knew from the start of the war that a massive invasion of mainland Europe would be critical. Since Operation Overlord was launched from England, the U.S. military had to ship 7 million tons of supplies to the staging area, including 450,000 tons of ammunition. The D-Day invasion began in the pre-dawn hours of June 6 with thousands of paratroopers landing inland on the Utah and Sword beaches in an attempt to cut off exits and destroy bridges to slow Nazi reinforcements. U.S. Army infantry men approaching Omaha Beach, Normandy, France on June 6, 1944. The first waves of American fighters were cut down in droves by German machine gun fire. At Omaha Beach, U.S. forces persisted through the day-long slog, pushing forward to a fortified seawall and then up steep bluffs to take out the Nazi artillery posts by nightfall. Anticipating an Allied invasion along the French coast, German forces had completed construction of the “Atlantic Wall,” a 2,400-mile line of bunkers, landmines and beach and water obstacles. Shown are massive landings at Omaha Beach after it was secured by U.S. troops. Barrage balloons keep watch overhead for German aircraft while scores of ships unload men and materials. Hitler’s Nazi regime built camps for genocide, aiming to eradicate Jews and others. These children were held at Auschwitz in Poland. A Wöbbelin concentration camp survivor weeps upon learning he won’t leave with the first group taken to the hospital after U.S. forces liberated the camp, 1945. Buchenwald survivors in their barracks after Allied liberation, April 1945. Elie Wiesel is on the second bunk from the bottom, seventh from left. Fifteen-year-old Ivan Dudnik was brought to Auschwitz from his home in the Oryol region of Russia by the Nazis. While being rescued, he had reportedly gone insane after witnessing mass horrors. In May 1945, Allied troops discover Holocaust victims in a railroad car that did not arrive at its final destination, believed to be the Wöbbelin concentration camp near Ludwigslust, Germany. A pile of human bones and skulls at Majdanek concentration camp near Lublin, Poland, in 1944. Majdanek was the second largest death camp in Nazi-occupied Poland after Auschwitz. A body lies in a crematory oven at Buchenwald near Weimar, Germany, in April 1945. The camp held Jews and many others, including prisoners of war and dissenters. Auschwitz camp, as seen in April 2015. Nearly 1.3 million people were deported to the camp, and more than 1.1 million perished. Prosthetic legs and crutches are a part of a permanent exhibition in the Auschwitz Museum. A pile of footwear are also a part of the Auschwitz Museum. Executive Order 9066 (Feb 1942) forced 117,000 Japanese Americans, including the Mochida family, into internment camps by June. After Pearl Harbor, a Japanese American in Oakland posted “I Am An American.” His shop was soon closed, and he was interned. Accommodations for Japanese Americans at the Santa Anita “reception center,” Los Angeles County, California, April 1942. March 21, 1942: The first 82 Japanese Americans arrived at Owens Valley camp, which later held over 10,000 internees. Children of the Weill public school are shown in a flag pledge ceremony in April 1942. Those of Japanese ancestry were soon moved to War Relocation Authority centers. A young Japanese American girl waiting to travel with her parents to Owens Valley, during the forced removal , April 1942. The last Redondo Beach residents of Japanese ancestry were forcibly moved out by truck to relocation camps. Crowds seen waiting for registration at Reception Centers in Santa Anita, California, April 1942. Japanese Americans were incarcerated in crowded conditions at Santa Anita. Risa and Yasubei Hirano pose with their son George (left) while holding a photo of their other son, Shigera Hirano. The Hiranos were held at the Colorado River camp while their sons served in the U.S. Army. A U.S. soldier guarding a crowd of Japanese Americans at an prisoner camp at Manzanar, California in 1944. Japanese American prisoners at the Gila River Relocation Center greet First Lady Eleanor Roosevelt and Dillon S Myer, director of the War Relocation Authority, on a tour of inspection in Rivers, Arizona. The concentration camp at Manzanar, Inyo County, California, July 3, 1942. On Aug. 6, 1945, the U.S. dropped “Little Boy” on Hiroshima, the first wartime atomic bomb, detonating with 15 kilotons of force. Crew of the B-29 Enola Gay, which dropped the first atomic bomb on Hiroshima, poses with pilot Col. Paul Tibbets and team. A view of the atomic bomb as it is hoisted into the bay of the Enola Gay on the North Field of Tinian airbase, North Marianas Islands, early August, 1945. Hiroshima lay in ruins after the Aug. 6, 1945 atomic blast. About 80,000 died instantly; up to 166,000 perished by year’s end. The plutonium bomb, nicknamed “Fat Man,” is shown in transport. It would be the second nuclear bomb dropped by U.S. forces in World War II. An Allied correspondent stands in rubble on September 7, 1945, looking to the ruins of a cinema after the atomic bomb attack on Hiroshima. Children in Hiroshima, Japan are shown wearing masks to combat the odor of death after the city was destroyed two months earlier. Survivors hospitalized in Hiroshima show their bodies covered with keloids caused by the atomic bomb. An estimated 45-60 million people lost their lives and millions more were injured in World War II. Here, Private Sam Macchia from NYC returns home, wounded in both legs, to his elated family. A parish priest waves a newspaper with news of Germany’s unconditional surrender to pupils of a Roman Catholic parochial school in Chicago. Merchant Marine Bill Eckert wildy impersonates Hitler as a reveler playfully chokes him amidst a crowd in Times Square during a massive V-E Day celebration. Young people in a car celebrate victory in Europe at the end of World War II, in Baltimore, Maryland, May 8, 1945. People crowd on top of a van during a V-E Day celebration in London. Patients at England’s Horley Military Hospital, all severely wounded in France and Italy, celebrate V-E Day with nursing staff. U.S. war veterans returning home from Europe, on a converted troop ship. Wall Street is jammed as Financial District workers celebrate the reported end of the war in Europe. Wounded veteran Arthur Moore looks up as he watches the ticker tape rain down from New York buildings. Private B. Potts of the Middlesex Regiment makes a “V” sign from the porthole of the hospital ship “Atlantis” as he arrives home from World War II with an injury. A British soldier arrives home to a happy wife and son after serving in World War II. Sailors and Washington, D.C. residents dance the conga in Lafayette Park, waiting for President Truman to announce the surrender of Japan in World War II. Soldiers hug while being lifted onto the shoulders of a crowd on VJ Day, in Newark, New Jersey, August 18, 1945. U.S. servicemen in the sick bay of the S.S. Casablanca smile and point to a newspaper on August 15, 1945 with the headline “JAPS QUIT!” after the Japanese surrender in World War II. An apartment house on 107th Street in New York City is decorated for celebration at the end of World War II (V-J Day). A V-J Day rally in New York City’s Little Italy on September 2, 1945. Local residents set fire to a heap of crates to celebrate the Japanese surrender at the end of World War II. Joyous American soldiers and WACS fresh from bed parade through the London night celebrating V-J Day and the end of WWII. A women jumps into the arms of a soldier upon his return from World War II, New York, NY, 1945. An American soldier with lipstick on his face after V-J day celebrations. Soldiers celebrating victory over Japan in Honolulu, Hawaii, August 15, 1945. The 42nd Regiment arrive back home to Hawaii on July 2, 1946. They are greeted by cheering friends and loved ones throwing leis. These Photos Depict the 'Miracle of Dunkirk' That Saved 338,000 Lives These photos show the chaos and courage of the 1940 evacuation, when hundreds of thousands of Allied troops escaped German forces by sea. 10 Photos From V-J Day Celebrations Around the World Victory over Japan Day ushered in peace after the devastation of World War II. The Deadliest Ship Disaster in History Wasn’t the Titanic The torpedoing of the German ocean liner *Wilhelm Gustloff* in 1945 led to the deaths of some 9,000 men, women and children. About the author HISTORY.com works with a wide range of writers and editors to create accurate and informative content. All articles are regularly reviewed and updated by the HISTORY.com team. Articles with the “HISTORY.com Editors” byline have been written or edited by the HISTORY.com editors, including Amanda Onion , Missy Sullivan , Christian Zapata, Cristiana Lombardo and Adrienne Donica. We strive for accuracy and fairness. But if you see something that doesn't look right, click here to contact us! HISTORY reviews and updates its content regularly to ensure it is complete and accurate. Citation Information