William Allen was also a founder member and a Director of the African Institution, the successor body to the Sierra Leone Company, sponsored by philanthropists to establish a colony in West Africa for slaves freed on a voluntary basis, through the abolitionists' efforts, in America. The work of the successor body began in 1808, when the colony had been handed to the Crown in return for the British Parliament passing legislation for its protection at about the same time as the passing in 1807 of the Act for the abolition of the slave trade.