Kammala jumla mai zuwa: Mann ya yi aiki tare da 17th Infantry Regiment a cikin Spanish-American War, shiga cikin
Yaƙin El Caney da Siege na Santiago. Ya sami lambar yabo ta Silver Star don aikin jaruntaka a El Caney. Mann kuma ya yi aiki a cikin Philippines a 1899 da farkon 1900s. Ya kammala karatunsa daga Kwalejin War Army a 1905.