
After the Pearl Harbor attacks, Calvin Graham enlisted in the U.S. Navy and had him serving during World War II. He earned the Bronze Star, the Purple Heart, and a few other awards. However he lost these awards when it came to light that he was only 12 when he joined and 15 by the end of the war. After writing to Congress, he got most of them back. He had all his honors restored in 1994, which was two years after he had died.
Lots of underaged kids served if they could get away with it.