Countryman played in the minor leagues in 1914, from 1916 to 1920 and from 1925 to 1926 for the San Antonio Bronchos (1914), Marlin Marlins (1916), Fort Worth Panthers (1917), Houston Buffaloes (1918), Greenville Spinners (1919–1920), Galveston Pirates (1919), Mount Pleasant Cats (1925) and Palestine Pals (1926). He managed the Cats in 1925 and the Pals in 1926, replacing Jack Stansbury in the latter campaign. He served in World War I.
Countryman was head coach of the Rice Owls baseball team in 1922 and 1923 and the Texas Agricultural and Mechanical Aggies baseball team in 1928 and 1929.
He had a career college coaching record of 28–31–3.
Countryman was born in Navasota, Texas and died in Houston, Texas on November 6, 1964(1964-1911-06) (aged 69).