World War II Fast FactsBy CNN LibraryUpdated 5:41 PM ET, Mon September 1, 2014World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – German troops march through occupied Warsaw, Poland, during World War II, circa 1939. September 1 marks the 75th anniversary of the start of World War II. In 1939, Germany invaded Poland. Denmark, Luxembourg, the Netherlands, Norway and Belgium soon came under German control, and when France fell less than a year later, Britain was the only nation left in Western Europe to oppose Adolf Hitler's Third Reich. Click through for key photos from the war.Hide Caption 1 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – A 1939 photo shows German Chancellor Adolf Hitler speaking to Nazi officials. Hide Caption 2 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – In Asia, Japanese troops occupy a strategic point on Chusan Island on July 14,1939, during the Sino-Japanese War. Japan signed the Tripartite Pact in 1940, formally allying with Germany and Italy, and by 1942 most of the Asian Pacific Rim had come under its domination.Hide Caption 3 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – German soldiers on the Esplanade du Trocadero view the Eiffel Tower in Paris during the German occupation, circa 1940. In June 1940, German troops marched into Paris, forcing the French government to surrender.Hide Caption 4 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – British Hawker Hurricanes fly in formation during the Battle of Britain in 1940. The planes were a first line of defense against German bombers attacking England. The battle, fought between July 10 and October 31, 1940, was the first major battle to be won in the air. The Royal Air Force's victory thwarted Hitler's plans for invading Britain.Hide Caption 5 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – Smoke rises behind Tower Bridge during the first mass daylight attack in London on September 7, 1940. The nightly German air raids over London became known as the Blitz.Hide Caption 6 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – Italian dictator Benito Mussolini, left, with Hitler, center, and other leading Nazis, visits Germany during the war. Italy and Germany formed an alliance before the outbreak of war, but Italy remained a non-belligerent until June 10, 1940, when it declared war on Britain and France. Fighting spread to Greece and North Africa.Hide Caption 7 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – German tanks and infantry attack Soviet positions on the eastern front. On June 22, 1941, Germany broke its Non-Aggression Pact with the Soviet Union, launching the bloodiest theater of the war. Though the estimates vary greatly, Russia suffered the most war casualties of any nation in World War II -- as many as 13.8 million military deaths. Estimates of civilian deaths from military action, crimes against humanity, starvation and disease are as high as 9 million.Hide Caption 8 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – A view of U.S. ships in Pearl Harbor, Hawaii, after the Japanese attack on December 7, 1941. The USS West Virginia and USS Tennessee are in the foreground. The attack destroyed more than half the fleet of aircraft and damaged eight battleships. Japan also attacked Clark and Iba airfields in the Philippines, destroying more than half the U.S. Army's aircraft there. Hide Caption 9 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – U.S. President Franklin D. Roosevelt signs the declaration of war against Japan on December 8, 1941. After it was signed, the two other Axis powers, Italy and Germany, immediately declared war on the United States. On December 11, Roosevelt signed the U.S. declarations of war against Germany and Italy. Hide Caption 10 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – British prisoners of war leave Hong Kong for a Japanese prison camp in December 1941.Hide Caption 11 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – Anti-aircraft fire glows over Algiers during a night raid on November 23, 1942. In 1942, the Allies stopped the Axis advance in North Africa and the Soviet Union. Hide Caption 12 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – Black smoke rises from demolished buildings after Japanese air forces attacked the U.S. Navy base on Midway Atoll during the Battle of Midway in June 1942. The four-day battle became a major victory for the U.S. Navy, which sunk four Japanese aircraft carriers, and it marked a major turning point in the war in the Pacific.Hide Caption 13 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – Balloon operators from Britain's Women's Auxiliary Air Force, or WAAF, report for inspection in a hangar used to store balloons, at a facility in the UK. During World War II, women played a significant role in the war effort. They took jobs in "defense plants and volunteered for war-related organizations, in addition to managing their households," according to the World War II museum in New Orleans.Hide Caption 14 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – British troops land near Algiers during Operation Torch in November 1942. Operation Torch was the British-American invasion of Vichy-held French North Africa, and marked the first major action by the Western allies against the German army.Hide Caption 15 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – Soviet soldiers advance against the German army during the Battle of Stalingrad. The battle for the city in on the Volga River (present-day Volgograd) was a major defeat for Germany and a turning point in the war. The lasted more than five months, ending in February 1943, at the cost of at least 160,000 German soldiers killed or captured. However, even conservative estimates of Russian casualties are much higher.Hide Caption 16 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – German prisoners captured at the beachhead of Anzio leave a landing craft on their way to a prison camp in 1944. The amphibious landing and ensuing battle helped Allied forces break a months-long stalemate south of Rome and ultimately defeat the Germans in Italy.Hide Caption 17 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – French refugees live in a quarry near Fleury sur Orne. During the bombing in that area, 20,000 refugees lived in the quarries. Hide Caption 18 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – U.S. troops assault Omaha Beach during the invasion of Normandy on June 6, 1944. D-Day, in which Allied forces landed on five beaches -- Utah, Omaha, Juno, Gold and Sword -- marked the beginning of a Western front in the European Theater. The landing included over 5,000 ships, 11,000 airplanes and 150,000 soldiers. More than 35,000 Allied troops were killed during the Normandy Campaign, which lasted till the end of August 1944.Hide Caption 19 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – A crowd gathers to cheer Gen. Charles de Gaulle at the Place de la Concorde on August 26, 1944, a day after the liberation of Paris.Hide Caption 20 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – Soldiers of an infantry division move into the mist over a snow-covered field near Krinkelter, Belgium, on December 20, 1944, during the Battle of the Bulge.Hide Caption 21 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – U.S. Marines of the 28th Regiment, 5th Division, raise the American flag atop Mount Suribachi, Iwo Jima, on February 23, 1945. Strategically located only 660 miles from Tokyo, the Pacific island was essential to launching land-based bombers against Japan. It was the bloodiest battle in the history of the U.S. Marine Corps, which suffered more than 27,000 casualties. Of some 18,000 Japanese soldiers defending the island, 216 survived.Hide Caption 22 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – German prisoners captured at Friedrichsfeld march through a town in Germany after the crossing of the Rhine River by the U.S. 9th Army on March 26, 1945.Hide Caption 23 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – From left, British Prime Minister Winston Churchill, U.S. President Franklin D. Roosevelt and Russian Premier Joseph Stalin at the Yalta Conference on February 1945. Hide Caption 24 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – Prisoners line block 61 of Buchenwald concentration camp in April 1945. The construction of Buchenwald started July 15, 1937, and the camp was liberated by U.S. Gen. George Patton's troops on April 11, 1945. Between 239,000 and 250,000 people were imprisoned in the camp. About 56,000 died, including 11,000 Jews. Hide Caption 25 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – President Franklin D. Roosevelt's funeral procession goes down Connecticut Avenue on its way to the White House. Roosevelt died on April 12, 1945, just weeks before Germany's surrender.Hide Caption 26 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – Harry S. Truman takes the oath of office on April 12, 1945, as he becomes the 33rd president of the United States. Standing beside him are his wife, Bess, and daughter Margaret.Hide Caption 27 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – The bodies of Benito Mussolini, left, and his mistress, Clara Petacci, second from left, hang from the roof of a gasoline station after they were shot by anti-Fascist forces while attempting to escape to Switzerland on April 28, 1945.Hide Caption 28 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – Russian soldiers wave their flag, made from tablecloths, over the ruins of the Reichstag in Berlin on April 30, 1945. That day, as the Soviets were within blocks of his bunker at the Reich Chancellery, Adolf Hitler committed suicide. Hide Caption 29 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – British Prime Minister Winston Churchill addresses the celebrating crowds from the balcony of the Ministry of Health in Whitehall, London, on V-E Day, May 8, 1945. The war in Europe is officially over.Hide Caption 30 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – Soldiers rush an injured U.S. Marine from a battlefield in Okinawa Island during the Battle of Okinawa in June 1945.Hide Caption 31 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – A photograph on display at the Bradbury Science Museum shows the first instant of the first atomic bomb test, on July 16, 1945, at 5:29 a.m. at Trinity Site in New Mexico. On July 29, 1945, President Harry Truman warned Japan that the country would be destroyed if it would not surrender unconditionally. Japan continued fighting.Hide Caption 32 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – Col. Paul W. Tibbets Jr., center, stands with the ground crew of the B-29 bomber "Enola Gay," which Tibbets piloted on August 6, 1945. The atomic bomb dropped on Hiroshima, Japan, that day killed 140,000 people. Hide Caption 33 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – The "shadow" of a victim remains in June 1946 on some steps, left, after the atomic bombing of the Japanese city of Hiroshima by the United States. The person had been sitting on the steps when the heat from the explosion burned the surface of the stone around the victim's body.Hide Caption 34 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – A dense column of smoke rises more than 60,000 feet into the air over the Japanese industrial port of Nagasaki, the result of an atomic bomb, the second ever used in warfare, on August 9, 1945. It was dropped from a U.S. Air Force B-29 Superfortress.Hide Caption 35 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – V-J Day: A jubilant American sailor hugs a nurse as he celebrates the news that Japan has surrendered, on August 14, 1945, with thousands of others in New York's Times Square. Hide Caption 36 of 37World War II: 75th anniversary 37 photosWorld War II: 75th anniversary – Japanese Foreign Minister Mamoru Shigemitsu signs the Japanese Instrument of Surrender on the deck of the USS Missouri in Tokyo Bay on September 2, 1945, in Japan, officially bringing World War II to an end. Overseeing the surrender is U.S. Gen. Douglas McArthur (right, back to camera).Hide Caption 37 of 37Here's what you need to know about World War II, which lasted from 1939 to 1945.Causes of World War II:The Peace of Paris - The treaties worked out in Paris at the end of World War I satisfied few. Germany, Austria, and the other countries on the losing side of the war were especially unhappy with the Paris Agreement, which required them to give up arms and make reparations. Germany agreed to sign the Treaty of Versailles only after the victorious countries threatened to invade if Germany did not sign it. Germany made the last payment on reparations in 2010. Economic Issues - World War I was devastating to countries' economies. Although the European economy had stabilized by the 1920s, the Great Depression in the United States led to economic downfall in Europe. Communism and fascism gained strength in the wake of economic problems. Nationalism - An extreme form of patriotism that grew in Europe became even stronger after World War I, especially for countries that were defeated. Just Watched75 years since outbreak of WWIIreplayMore Videos ...75 years since outbreak of WWII 01:21PLAY VIDEOJust WatchedUnderwater cameras caputure WWII shipwrecksreplayMore Videos ...Underwater cameras caputure WWII shipwrecks 03:14PLAY VIDEOJust WatchedVets who fought on D-Day share memoriesreplayMore Videos ...Vets who fought on D-Day share memories 02:49PLAY VIDEODictatorships - Political unrest and unfavorable economic conditions lead to the rise of dictatorships in countries such as Germany, Italy, Japan and the Soviet Union.Failure of Appeasement - Czechoslovakia had become an independent nation after World War I, but by 1938, was surrounded by German territory. Hitler wanted to annex the Sudetenland, an area in western Czechoslovakia where many Germans lived. British Prime Minister Neville Chamberlain wanted to appease Hitler and agreed to his demands for the Sudetenland after Hitler promised he would not demand more territory. Hitler seized the rest of Czechoslovakia in March of 1939.Axis Powers:Germany, Japan, and Italy formed a coalition called the Axis Powers. Bulgaria, Hungary, Romania, and two German-created states--Croatia and Slovakia--eventually joined.Major Players:Germany - Adolf Hitler, Der FurherJapan - Admiral Hideki Tojo, Prime MinisterItaly - Benito Mussolini, Prime MinisterAllied Powers:The United States, Great Britain, China and the Soviet Union made up the Allies, the group fighting the Axis. Between 1939 and 1944 at least 50 nations would eventually fight together. Thirteen more nations would join by 1945 including: Australia, Belgium, Brazil, British Commonwealth of Nations, Canada, India, New Zealand, South Africa, Czechoslovakia, Denmark, France, Greece, Netherlands, Norway, Poland, Philippines, and Yugoslavia.Major players:United States - Franklin D. Roosevelt, President Great Britain - Winston Churchill, Prime Minister China - Chiang Kai-Shek, General Soviet Union - Joseph Stalin, GeneralU.S. Troop Statistics:16,112,566 - Number of U.S. troops that served in the conflict.670,846 - Number of U.S. wounded.U.S. Deaths:Battle: 291,557Non-Battle: 113,842Total In-Theatre: 405,399Other Military Casualties by Country 1939-1945 (selected):Australia: 23,365 dead; 39,803 woundedAustria: 380,000 dead; 350,117 woundedBelgium: 7,760 dead; 14,500 woundedBulgaria: 10,000 dead; 21,878 woundedCanada: 37,476 dead; 53,174 woundedChina: 2,200,000 dead; 1,762,000 woundedFrance: 210,671 dead; 390,000 woundedGermany: 3,500,000 dead; 7,250,000 woundedGreat Britain: 329,208 dead; 348,403 woundedHungary: 140,000 dead; 89,313 woundedItaly: 77,494 dead; 120,000 woundedJapan: 1,219,000 dead; 295,247 woundedPoland: 320,000 dead; 530,000 woundedRomania: 300,000 dead; wounded unknownSoviet Union: 7,500,000 dead; 5,000,000 woundedUnited States: 405,399 dead; 670,846 woundedOther Facts:About 70 million people fought in the armed forces of the Allied and Axis nations.Finland never officially joined either the Allies or the Axis and was at war with the Soviet Union at the outbreak of World War II. Needing help in 1940, the Finnish joined forces with Nazi Germany to repel the Soviets. When peace between Finland the Soviet Union was declared in 1944, Finland joined with the Soviets to oust the Germans.Switzerland, Spain, Portugal and Sweden declared neutrality during the war.The Soviet Union lost the most soldiers, in excess of seven million.The number of civilian casualties in World War II may never be known. Many deaths were caused by bombing raids, massacres, starvation and other war-related causes.It is believed that approximately six million Jewish people died in Nazi concentration camps during the war. Also killed were hundreds of thousands of Roma people and people with mental or physical disabilities. The Lend-Lease Act was created to allow the United States to lend or lease weapons, equipment, or raw materials to any nation fighting the Axis. Eventually, 38 nations received about $50 billion in aid. Most went to Great Britain and the Soviet Union. In 1948, the United States created the Marshall Plan to help rebuild war torn Europe. Eventually, 18 nations received $13 billion in food, machinery and other goods. In March of 1974, Hiroo Onoda, a Japanese soldier still fighting the war, was found by a search party on the island of Lubang in the Philippines. After he is convinced the war is over by his former commanding officer he is then flown to Manila and formally surrenders to President Ferdinand Marcos. Mr. Onoda died January 16, 2014, at the age of 91.Timeline:September 1, 1939 - Germany invades Poland. Denmark, Luxembourg, the Netherlands, Norway, Belgium, and France soon fall into German control, until only the United Kingdom is left to face Germany. June 10, 1940 - Italy joins the war on the side of Germany by declaring war against Britain (UK) and France. Fighting spreads to Greece and Northern Africa.June 14, 1940 - German troops march into Paris.July 1940-September 1940 - Germany and Great Britain fight an air war, the Battle of Britain, along the English coastline.September 7, 1940-May 1941 - German bombing campaign of nightly air raids over London, known as the Blitz.January 22, 1941 - British and Commonwealth troops take over the port city of Tobruk, Libya. June 22, 1941 - Germany invades the Soviet Union.September 1941 - Japanese troops invade Indochina.December 7, 1941 - Japan attacks Pearl Harbor, destroying more than half of the fleet of aircraft, and damaging all eight battleships. Japan also attacks Clark and Iba airfields in the Philippines destroying over half of the U.S. Army's aircraft there. December 8, 1941 - President Franklin D. Roosevelt delivers the "a date which will live in infamy" speech to Congress, and the U.S declares war on Japan. Japan invades Hong Kong, Guam, the Wake Islands, Singapore, and British Malaya. December 11, 1941 - Germany and Italy declare war on the United States.By Christmas 1941, Japan had taken Thailand, Guam, Hong Kong, and Wake Island.1942 - The Allies stop the Axis Powers' advance in Northern Africa and the Soviet Union.February 1942 - Japan invades the Malay Peninsula. Singapore surrenders within a week.June 4-6, 1942 - Japan's plans to invade the Hawaiian Islands, starting at Midway Island, but the United States cracks the code of the mission. Japan attacks Midway and loses four aircraft carriers and over 200 planes and pilots in the first clear victory for the United States.August 19, 1942 - The battle for Stalingrad begins as Germany pushes further into Russia.August 1942-February 1943 - U.S. Marines fight for and hold the Pacific island of Guadalcanal.October 23, 1942 - British troops push Axis troops into retreating to Tunisia in the Second Battle of El Alamein. February 1, 1943 - The German troops in Stalingrad surrender, defeated in large part by the Soviet winter. The defeat marks the halt of Germany's eastbound advance.July 10, 1943 - Allied forces land in Italy. July 25, 1943 - The King of Italy is restored to full power, and Mussolini is deposed and arrested.Just WatchedStephen Colbert's emotional D-Day storyreplayMore Videos ...Stephen Colbert's emotional D-Day story 06:44PLAY VIDEOJust WatchedA timeline of World War IIreplayMore Videos ...A timeline of World War II 03:29PLAY VIDEONovember 1943-March 1944 - U.S. Marines invade the Solomon Islands at Bougainville to recapture it from the Japanese.Just WatchedViewing WWII through a soldier's lensreplayMore Videos ...Viewing WWII through a soldier's lens 03:01PLAY VIDEOJune 6, 1944 - D-Day, in which Allied forces land on five beaches at Normandy: Utah, Omaha, Gold, Juno and Sword. The landing includes over 5,000 ships, 11,000 airplanes and over 150,000 service men.August 25, 1944 - American and Free French forces liberate Paris.January 27, 1945 - Soviet troops liberate the Auschwitz camp complex, located near Krakow, Poland. February 19-March 26, 1945 - U.S. Marines battle the Japanese for the island of Iwo Jima.April 12, 1945 - President Roosevelt dies in Warm Springs, Georgia. Vice President Harry Truman takes the oath of office as president. April 25, 1945 - Soviet troops surround Berlin.April 28, 1945 - Mussolini is killed attempting to escape to Switzerland.April 29, 1945 - U.S. soldiers liberate the Dachau concentration camp outside of Munich, Germany. April 30, 1945 - Hitler and wife Eva Braun commit suicide.May 7, 1945 - Germany surrenders in a red school house in Reims, Germany, Eisenhower's headquarters. V-E Day is celebrated on May 8 because that was the day the armistice went into effect.May 8, 1945 - V-E Day, Victory in Europe. The war in Europe is officially over.July 16, 1945 - First successful test of the atomic bomb in Alamogordo, New Mexico. July 29, 1945 - President Harry Truman warns Japan that the country will be destroyed if it does not surrender unconditionally. Japan continues fighting.August 6, 1945 - The first atomic bomb used in warfare, nicknamed Little Boy, is dropped on the Japanese city of Hiroshima, killing up to 140,000 people.August 9, 1945 - After getting no response from the Japanese government after the Hiroshima bombing, a second atomic bomb, nicknamed Fat Man, is dropped on Nagasaki, killing up to 80,000 people.August 14, 1945 - Japan unconditionally agrees to accept the terms of the Potsdam Declaration and end the war. V-J Day, Victory over Japan, is declared.September 2, 1945 - Japan signs the formal surrender aboard the USS Missouri in Tokyo Bay. More from worldDozens missing in mine explosion in UkraineEgyptian conspiracies link U.S. and ISISWelcome to Japan's 'Cat Island'