World War II: The 99th Pursuit Squadron also known as the Tuskegee Airmen, the first all-black unit of the US Army Air Corps, is activated.

The Tuskegee Airmen were a group of primarily African American military pilots (fighter and bomber) and airmen who fought in World War II. They formed the 332d Fighter Group and the 477th Bombardment Group (Medium) of the United States Army Air Forces (USAAF). The name also applies to the navigators, bombardiers, mechanics, instructors, crew chiefs, nurses, cooks, and other support personnel.

All black military pilots who trained in the United States trained at Griel Field, Kennedy Field, Moton Field, Shorter Field, and the Tuskegee Army Air Fields. They were educated at the Tuskegee Institute (now Tuskegee University), located near Tuskegee, Alabama. Of the 922 pilots, five were Haitians from the Haitian Air Force and one pilot was from Trinidad. It also included a Hispanic or Latino airman born in the Dominican Republic.The 99th Pursuit Squadron (later the 99th Fighter Squadron) was the first black flying squadron, and the first to deploy overseas (to North Africa in April 1943, and later to Sicily and other parts of Italy). The 332nd Fighter Group, which originally included the 100th, 301st and 302nd Fighter Squadrons, was the first black flying group. It deployed to Italy in early 1944. Although the 477th Bombardment Group trained with North American B-25 Mitchell bombers, they never served in combat. In June 1944, the 332nd Fighter Group began flying heavy bomber escort missions and, in July 1944, with the addition of the 99th Fighter Squadron, it had four fighter squadrons.

The 99th Fighter Squadron was initially equipped with Curtiss P-40 Warhawk fighter-bomber aircraft. The 332nd Fighter Group and its 100th, 301st and 302nd Fighter Squadrons were equipped for initial combat missions with Bell P-39 Airacobras (March 1944), later with Republic P-47 Thunderbolts (JuneJuly 1944) and finally with the aircraft with which they became most commonly associated, the North American P-51 Mustang (July 1944). When the pilots of the 332nd Fighter Group painted the tails of their P-47s red, the nickname "Red Tails" was coined. The red markings that distinguished the Tuskegee Airmen included red bands on the noses of P-51s as well as a red rudder; the P-51B, C and D Mustangs flew with similar color schemes, with red propeller spinners, yellow wing bands and all-red tail surfaces.

The Tuskegee Airmen were the first African-American military aviators in the United States Armed Forces. During World War II, black Americans in many U.S. states were still subject to the Jim Crow laws and the American military was racially segregated, as was much of the federal government. The Tuskegee Airmen were subjected to discrimination, both within and outside of the army.

World War II or the Second World War, often abbreviated as WWII or WW2, was a global war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies and the Axis powers. In a total war directly involving more than 100 million personnel from more than 30 countries, the major participants threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and the only two uses of nuclear weapons in war. World War II was by far the deadliest conflict in human history; it resulted in 70 to 85 million fatalities, a majority being civilians. Tens of millions of people died due to genocides (including the Holocaust), starvation, massacres, and disease. In the wake of the Axis defeat, Germany and Japan were occupied, and war crimes tribunals were conducted against German and Japanese leaders.

The exact causes of World War II are debated, but contributing factors included the Second Italo-Ethiopian War, the Spanish Civil War, the Second Sino-Japanese War, the Soviet–Japanese border conflicts and rising European tensions since World War I. World War II is generally considered to have begun on 1 September 1939, when Nazi Germany, under Adolf Hitler, invaded Poland. The United Kingdom and France subsequently declared war on Germany on 3 September. Under the Molotov–Ribbentrop Pact of August 1939, Germany and the Soviet Union had partitioned Poland and marked out their "spheres of influence" across Finland, Estonia, Latvia, Lithuania and Romania. From late 1939 to early 1941, in a series of campaigns and treaties, Germany conquered or controlled much of continental Europe, and formed the Axis alliance with Italy and Japan (along with other countries later on). Following the onset of campaigns in North Africa and East Africa, and the fall of France in mid-1940, the war continued primarily between the European Axis powers and the British Empire, with war in the Balkans, the aerial Battle of Britain, the Blitz of the UK, and the Battle of the Atlantic. On 22 June 1941, Germany led the European Axis powers in an invasion of the Soviet Union, opening the Eastern Front, the largest land theatre of war in history.

Japan, which aimed to dominate Asia and the Pacific, was at war with the Republic of China by 1937. In December 1941, Japan attacked American and British territories with near-simultaneous offensives against Southeast Asia and the Central Pacific, including an attack on the US fleet at Pearl Harbor which resulted in the United States declaring war against Japan. Therefore the European Axis powers declared war on the United States in solidarity. Japan soon captured much of the western Pacific, but its advances were halted in 1942 after losing the critical Battle of Midway; later, Germany and Italy were defeated in North Africa and at Stalingrad in the Soviet Union. Key setbacks in 1943—including a series of German defeats on the Eastern Front, the Allied invasions of Sicily and the Italian mainland, and Allied offensives in the Pacific—cost the Axis powers their initiative and forced it into strategic retreat on all fronts. In 1944, the Western Allies invaded German-occupied France, while the Soviet Union regained its territorial losses and turned towards Germany and its allies. During 1944 and 1945, Japan suffered reversals in mainland Asia, while the Allies crippled the Japanese Navy and captured key western Pacific islands.

The war in Europe concluded with the liberation of German-occupied territories, and the invasion of Germany by the Western Allies and the Soviet Union, culminating in the fall of Berlin to Soviet troops, Hitler's suicide and the German unconditional surrender on 8 May 1945. Following the Potsdam Declaration by the Allies on 26 July 1945 and the refusal of Japan to surrender on its terms, the United States dropped the first atomic bombs on the Japanese cities of Hiroshima, on 6 August, and Nagasaki, on 9 August. Faced with an imminent invasion of the Japanese archipelago, the possibility of additional atomic bombings, and the Soviet’s declared entry into the war against Japan on the eve of invading Manchuria, Japan announced on 15 August its intention to surrender, then signed the surrender document on 2 September 1945, cementing total victory in Asia for the Allies.

World War II changed the political alignment and social structure of the globe. The United Nations (UN) was established to foster international co-operation and prevent future conflicts, with the victorious great powers—China, France, the Soviet Union, the United Kingdom, and the United States—becoming the permanent members of its Security Council. The Soviet Union and the United States emerged as rival superpowers, setting the stage for the nearly half-century-long Cold War. In the wake of European devastation, the influence of its great powers waned, triggering the decolonisation of Africa and Asia. Most countries whose industries had been damaged moved towards economic recovery and expansion. Political and economic integration, especially in Europe, began as an effort to forestall future hostilities, end pre-war enmities and forge a sense of common identity.