Congress changes draft age, Nov. 11, 1942 – POLITICO

Congress changes draft age, Nov. 11, 1942. Registration of men between the ages of 21 and 36 began that October. Two years later, with the United States an active participant in World War II, George Marshall, the Army chief of staff, urged President Franklin D. Roosevelt to support a reduction in the draft age to 18.

https://www.politico.com/story/2014/11/this-day-in-politics-congress-draft-november-11-1942-112752