Born in Lincoln, Nebraska, Mann attended the Y.M.C.A. College in 1914 "Miracle" Braves team that went from last place to first place in two months, becoming the first team to win a pennant after being in last place on the Fourth of July.
Born in Lincoln, Nebraska, Mann attended the Y.M.C.A. College in Boston Braves, St. Louis Cardinals, Cincinnati Reds, New York Giants, and Chicago Cubs. He was a member of the 1914 "Miracle" Braves team that went from last place to first place in two months, becoming the first team to win a pennant after being in last place on the Fourth of July.