Africanus Horton joined the British Army Medical Service the year he completed his medical studies, and was appointed Assistant Staff Surgeon. He was one of the first Africans to qualify as a medical doctor, and one 'of the first to serve as an officer in the British Army. He continued in the Army for the next twenty-one years, attaining the rank of Lieutenant-Colonel. He spent most of that time in the Gold Coast (Ghana), where he took an active interest in scientific research. He published several studies involving tropical diseases, climate and meteorology, and geology. But despite his dedicated and professionally competent service, the British authorities were not anxious to see an African advance too far. They shifted Horton constantly from one post to another, and rejected his application in 1872 for the position of Governor of the Gold Coast. Despite his disappointments, Horton continued to believe that Africans could advance under the banner of British colonialism. In 1865, a Select Committee of the British House of Commons had suggested that Africans be given increasing responsibility for administering their own affairs. The same year, Horton published Political Economy of British Western Africa, a book calling for the establishment of a West African University along British lines. Three years later, he published his popular West African Countries and Peoples, calling for nothing less than the establishing of independent West African nations in the Gambia, Sierra Leone, etc. He argued for British assistance in moving these African countries toward self-rule, and presented plans for education, economic development, and medical improvements, but the Select Committee's recommendations were not popular with British authorities who looked toward increasing their control, not decreasing it - and Horton began to be seen as an enemy of British policy.
Africanus Horton retired from the Army in 1880, and returned to Freetown. Ever the optimist and believer in progress, he set up a commercial bank to assist struggling African entrepreneurs.
