Nicknamed "The Colonel" because he was a U.S. Marine Corps lieutenant colonel, Coleman was a Marine aviator who postponed his entry into professional baseball in World War II and later left baseball to serve in the Korean War. While a Marine Corps aviator he flew 120 combat missions (57 during World War II and 63 in Korea). and received numerous honors and medals including two Distinguished Flying Crosses. In the years before his death, Coleman received numerous honors, including induction into the USMC Sports Hall of Fame, for his call to duty. Coleman was the only Major League Baseball player to see combat in two wars. (While Ted Williams served during both World War II and Korea, he flew combat missions only in the Korean War.)