Ronald Reagan, in December 1941, right after the U.S. entered into World War II. Reagan enlisted in the Army Enlisted Reserve and was commissioned a second lieutenant in the Officers Reserve Corps of the cavalry on May 25, 1937. He was ordered to active duty for the first time on April 18, 1942. Due to his poor eyesight, he was classified for limited service only, which excluded him from serving overseas. His first assignment was at the San Francisco Port of Embarkation at Fort Mason, California, as a liaison officer of the Port and Transportation Office. He applied for a transfer from the cavalry to the Army Air Force on May 15, 1942, and was assigned to AAF Public Relations and subsequently to the First Motion Picture Unit. While with the First Motion Picture Unit in 1945, he was indirectly involved in discovering actress Marilyn Monroe. By the end of the war, his units had produced some 400 training films for the AAF.

12/1941