Dennis Wilson Graham was born in Proctorville, North Carolina, on June 14, 1896. At the time he registered for the draft—on June 5, 1918—he was playing semi-pro with the Havana Red Sox. He entered the Student Army Training Corps stationed at Shaw University on October 30, 1918. Just twelve days later, the armistice ending World War I took effect, and Graham was discharged from service as part of rapid demobilization efforts on December 20, 1918. He graduated from Shaw in May 1920.

Graham was a professional baseball player in 1921 and 1924 to 1930, playing for the Atlantic City Bacharach Giants and the Homestead Grays. By 1930, Graham had relocated to Pittsburgh, Pennsylvania where he was employed as a porter for a railroad company. He died there on December 2, 1967.