"The Drummer Boy of Chickamauga" was 12 years old when he was promoted to sergeant after firing on a Confederate colonel who was attempting to capture him. At that point John Lincoln Clem became the youngest non-commissioned officer in U.S. history and a Civil War hero.
Born John Joseph Klem in 1851 to immigrant parents, he later changed his name to John Lincoln Clem out of admiration for Abraham Lincoln and because he thought "Clem" would appear more American than "Klem." When the Civil War kicked off, the young Ohio native immediately tried to join the Union Army.
Clem was a 9-year-old when he attempted to enlist as a drummer with the 3rd Ohio Regiment but was turned down because, duh, he was 9. He tried to join a few more units before being accepted at the age of 10 by the 22nd Michigan Infantry Regiment whose motto probably wasn't "What Child Endangerment?"
Despite allowing Clem to march to war with them, the 22nd knew the Army would not agree to pay such a young soldier. Officers of the unit collected donations to keep the kid in juice boxes and bullets until he turned 13 and could officially enlist.
His early battlefield biography is hazy, with some histories putting him at the Battle of Shiloh in the 22nd Michigan Infantry. The 22nd did not yet exist when that battle was fought.
Regardless, Clem participated at the Battle of Chickamauga from Sep. 19-20, 1863 where he was nearly captured before using his sawed-off musket, a custom gift from unit officers, to shoot down the mounted Confederate colonel who was chasing him. His hat was reportedly shot through three times during the battle and his escape from Confederate pursuers.
He made it back to Union lines and received a promotion to sergeant, making him the youngest ever.
His actions at Chickamauga were published in newspapers around the North and he became a celebrity. Unfortunately, his celebrity status worked against him a month later when he was captured by Confederate cavalry who took away his hat with the three bullet holes.
Clem was swapped in a prisoner exchange and sent to serve as a mounted orderly for Maj. Gen. George H. Thomas. He saw action at Perryville, Murfreesboro, Kennesaw, and Atlanta. In the Battle of Atlanta, he was wounded twice. He was initially discharged at the age of 13 in 1864.
In 1870, Clem attempted to enter West Point but failed the entrance exam multiple times. President Ulysses S. Grant commissioned Clem as a second lieutenant in 1871, ignoring the fact that Clem couldn't pass the tests.
Clem went on to serve until 1915, mostly as an Army quartermaster. He was the last Civil War vet still on active duty when he retired as a brigadier general.