John Clem

John Lincoln Clem (nicknamed Johnny Shiloh; August 13, 1851 – May 13, 1937) was an American general officer who served as a drummer boy in the Union Army during the American Civil War. He gained fame for his bravery on the battlefield, becoming the youngest noncommissioned officer in the history of the United States Army at the age of 12.

He retired from the Army in 1915, having attained the rank of brigadier general in the Quartermaster Corps; he was at that time the last veteran of the American Civil War still on duty in the United States Armed Forces, although others similarly aged and experienced such as Peter Conover Hains and Albert A. Michelson rejoined the military after American entry into World War I in 1917.

By special act of Congress on August 29, 1916, he was promoted to major general on the retired list. Provided by Wikipedia