For his services in America, Bartholomew was promoted to post captain and made a Companion of the Order of the Bath. At the end of the Napoleonic Wars, Bartholomew's abilities as a surveyor and cartographer were required and he was given command of the small frigate HMS "Leven" off the West coast of Africa, charged with preparing detailed and accurate charts of the region. "Leven"'s officers were all young geographers, many of whom would later achieve prominence in the field, including Alexander Vidal, William Mudge, Alexander Becher and George Frazer. Bartholomew had successfully surveyed the Azores, stretches of West Africa and was working on the Cape Verde Islands when he fell ill with tuberculosis in 1821 and died at Porto Praya on Santiago. The expedition to West Africa was taken over by William Fitzwilliam Owen, but by its completion in 1825, over half the crew had died from tropical illnesses, including Bartholomew and his teenage son George, who died on "Leven" in 1819. He has been described as "One of the unsung heroes of the surveying service" and is also considered exceptional for his rise from an impressed sailor to post captain at a time when this was almost impossible to achieve.