In the United States of America, military conscription, commonly known as the draft, has been employed by the U.S. federal government in six conflicts: the American Revolutionary War, the American Civil War, World War I, World War II, the Korean War, and the Vietnam War. The fourth incarnation of the draft came into being in 1940, through the Selective Training and Service Act; this was the country's first peacetime draft. From 1940 until 1973, during both peacetime and periods of conflict, men were drafted to fill vacancies in the U.S. Armed Forces that could not be filled through voluntary means. Active conscription in the United States ended in 1973, when the U.S. Armed Forces moved to an all-volunteer military. However, conscription remains in place on a contingency basis; all male U.S. citizens, regardless of where they live, and male immigrants, whether documented or undocumented, residing within the United States, who are 18 through 25 are required to register with the Selective Service System. United States federal law also continues to provide for the compulsory conscription of men between the ages of 17 and 44 who are, or who have made a declaration of intention to become, U.S. citizens, and additionally women in certain health care occupations, for militia service pursuant to Article I, Section 8 of the United States Constitution and 10 U.S. Code § 246.

The Selective Training and Service Act of 1940, also known as the Burke–Wadsworth Act, Pub. L.Tooltip Public Law  76–783, 54 Stat. 885, enacted September 16, 1940, was the first peacetime conscription in United States history. This Selective Service Act required that men who had reached their 21st birthday but had not yet reached their 36th birthday register with local draft boards. Later, when the U.S. entered World War II, all men from their 18th birthday until the day before their 45th birthday were made subject to military service, and all men from their 18th birthday until the day before their 65th birthday were required to register.