Ephraim Graham attended the US Military Academy at West Point, graduating in 1903, and captaining the baseball team in his senior year. He was later an officer with the 10th US Cavalry Regiment, also known as the Buffalo Soldiers. He also taught at West Point as a Cavalry Instructor in Tactics. Graham played polo, in addition to equestrian competitions, and the polo team he led from the 10th Cavalry Regiment was considered the top Army team of the 1910s. In 1916 Col. Graham was severely injured during a polo match. He was left somewhat handicapped but served 16 more years of active duty, with tours at Fort Ethan Allen, Vermont; Schofield barracks in Hawai’i; and Forts Bliss and Sam Houston in Texas. Graham’s son, Ephraim, Jr., also became a career Army officer, serving with the 644th Tank Destroyer Battalion in World War II.