Calvin Graham, photographed during his U.S. Navy service in World War II, is remembered as the youngest known American serviceman to serve and fight in the conflict. Born in 1930, Graham enlisted at just 12 years old by falsifying his age after the attack on Pearl Harbor. He served aboard the USS South Dakota, taking part in major Pacific battles, including the Naval Battle of Guadalcanal in 1942, where he was wounded. His age was later discovered, leading to his discharge, but decades afterward

USS Constitution - Boston National Historical Park (U.S. National Park Service)