Major-General James Henry Craig, who was acting governor at the Cape from 1795 to 1797, discovered that Thibault was compiling a map of the Colony. Craig proposed that Thibault donate the map to him in return for the position of royal geographical engineer – an offer which Thibault declined, also turning down a later offer of 100 guineas. Craig was succeeded by Earl Macartney and Major-General Francis Dundas. In 1799 Dundas put Thibault in charge of repairs to military buildings as an architect. When Sir George Yonge, 5th Bt (1731–1812) replaced Dundas as Governor, he appointed Thibault as architect of military works under his aide-de-camp.