In January 1942, Illinois Sen. Barak Obama's 24-year-old grandfather, Stanley Dunham, said goodbye to his wife and infant and enlisted in the U.S. Army. "He signed up for duty, joined Patton's army and marched across Europe," said Sen. Obama of his grandfather's service. But Obama's American military heritage extends further back.

In 1917, Obama's great-grandfather Rolla Payne registered for the WWI draft. This 24-year-old bookkeeper worked for an oil well supply company in Tulsa, Oklahoma and would be called up to serve in the First World War. (Another great-grandfather and a great-great-grandfather also registered for the draft, although neither served in the Great War.)

Obama's great-great-great-grandfather Robert Wolfey served in the Ohio Infantry during the Civil War. This Union soldier kept the rank of private throughout his service.