Welshman Henry Morton Stanley — famous for seeking explorer David Livingstone in Africa — fought on both sides in the American Civil War.

In April 1862, when just 21 years old, he fought in the Confederate Army’s 6th Arkansas infantry regiment at the Battle of Shiloh. Captured, he swore allegiance to the United States and joined the Union Army in June. He was discharged after two weeks’ service due to severe illness, but recovered and went on to join the U.S. Navy in 1864.

In The Galvanized Yankees, Dee Brown writes, Stanley “probably became the only man ever to serve in the Confederate Army, the Union Army, and the Union Navy.”