The Air Corps Tactical School, also known as ACTS and "the Tactical School", was a military professional development school for officers of the United States Army Air Service and United States Army Air Corps, the first such school in the world. Created in 1920 at Langley Field, Virginia, it relocated to Maxwell Field, Alabama, in July 1931. Instruction at the school was suspended in 1940, anticipating the entry of the United States into World War II, and the school was dissolved shortly after. ACTS was replaced in November 1942 by the Army Air Force School of Applied Tactics.

The United States Army Air Service (USAAS) was the aerial warfare service component of the United States Army between 1918 and 1926 and a forerunner of the United States Air Force. It was established as an independent but temporary branch of the U.S. War Department during World War I by two executive orders of President Woodrow Wilson: on May 24, 1918, replacing the Aviation Section, Signal Corps as the nation's air force; and March 19, 1919, establishing a military Director of Air Service to control all aviation activities. Its life was extended for another year in July 1919, during which time Congress passed the legislation necessary to make it a permanent establishment. The National Defense Act of 1920 assigned the Air Service the status of "combatant arm of the line" of the United States Army with a major general in command.