The Enrollment Act of 1863 (, enacted March 3, 1863) also known as the Civil War Military Draft Act, was an Act passed by the United States Congress during the American Civil War to provide fresh manpower for the Union Army. The Act was the first genuine national conscription law. The law required the enrollment of every male citizen and those immigrants (aliens) who had filed for citizenship, between 20 and 45 years of age, unless exempted by the Act. The Act replaced the Militia Act of 1862.