World War II: During the second raid on Schweinfurt, the U.S. 8th Air Force suffered so many losses that it lost air supremacy over Germany for several months.

World War II or the Second World War was a global conflict between two coalitions: the Allies and the Axis powers. Nearly all of the world's countries participated, with many nations mobilising all resources in pursuit of total war. Tanks and aircraft played major roles, enabling the strategic bombing of cities and delivery of the first and only nuclear weapons ever used in war. World War II is the deadliest conflict in history, causing the death of 70 to 85 million people, more than half of whom were civilians. Millions died in genocides, including the Holocaust, and by massacres, starvation, and disease. After the Allied victory, Germany, Austria, Japan, and Korea were occupied, and German and Japanese leaders were tried for war crimes.

The second Schweinfurt raid, also called Black Thursday, was a World War II air battle that took place on 14 October 1943, over Nazi Germany between forces of the United States 8th Air Force and German Luftwaffe fighter arm (Jagdwaffe). The American bombers conducted a strategic bombing raid on ball bearing factories to reduce production of these vital parts used in all manner of war machines. This was the second attack on the factories at Schweinfurt. American wartime intelligence claimed the first Schweinfurt–Regensburg mission in August had reduced bearing production by 34 percent but had cost many bombers. A planned follow-up raid had to be postponed to rebuild American forces.

The Eighth Air Force (Air Forces Strategic) is a numbered air force (NAF) of the United States Air Force's Air Force Global Strike Command (AFGSC). It is headquartered at Barksdale Air Force Base, Louisiana. The command serves as Air Forces Strategic – Global Strike, one of the air components of United States Strategic Command (USSTRATCOM). The Eighth Air Force includes the heart of America's heavy bomber force: the Northrop Grumman B-2 Spirit stealth bomber, the Rockwell B-1 Lancer supersonic bomber, and the Boeing B-52 Stratofortress heavy bomber aircraft.