Draft card. Courtesy of Joseph Corrigan, C Troop, 2nd Squadron, 1st Cavalry Regiment, 4th Infantry Division, Dak To, Vietnam 1967–68
President Johnson’s order to send more troops to Vietnam affected all men between the ages of 18 and 26. Registration for military service was compulsory. The Selective Service called up only the men needed while excusing the rest through deferments. Twenty-seven million American men were of draft age during the war. Forty percent served in the military, and about 2.5 million went to Vietnam.