Selective Service Act
The Selective Service Act established the first peacetime draft in United States history. The Act passed the United States Congress on May 18, 1917 and gave the President the power to draft soldiers.
The draft began in November 1940, a year before the United States formally entered World War II. Conscription was not considered involuntary servitude under the Thirteenth Amendment, but rather part of Congress's right to raise and support armies.
Though the United States halted conscription in 1973, the Selective Service remains as a means to register American males upon reaching the age of 18 as a contingency should the measure be reintroduced.
See also: Conscription in the United States