 In 1798 he was appointed Colonel of the Ross-shire Regiment of Militia.Seaforth served as Governor of Barbados from 1800 to 1806, during which period he reformed slavery on the island, established a prohibition of the killing of slaves, and reduced official discrimination against free blacks.As Governor of Barbados, Seaforth appointed Thomas Moody, a mathematical expert, from a distinguished British imperialist family, who taught at Codrington College, to a direct commission in the Royal Engineers, which Moody entered as a lieutenant in 
1806.