 Castellow served as superintendent of the Coleman public schools in 1897 and 1898, captain in the Georgia State Troops, from 1899 until 1902 and solicitor of Clay County, Georgia court from 1900 through 1901.From 1901 until 1905, Castellow was judge of the Clay County court.He then moved to Cuthbert, Georgia, in 1906 to become a Referee in Bankruptcy for the western division of the northern district of Georgia.