American naval officer Matthew Calbraith Perry was the executive officer aboard in 1819, which had escorted the "Elizabeth", whose passengers included former slaves moving from the United States to Africa. President James Monroe had the Secretary of the Navy order the American vessel to convoy the "Elizabeth" to Africa with the first contingent of freed slaves that the American Colonization Society was resettling there. Of the 86 black emigrants sailing on the Elizabeth, only about one-third were men; the rest were women and children. In 1821, Perry commanded "Shark" in the Africa Squadron. "Alligator" under the command of Lieutenant Robert F. Stockton was also in the African Squadron in 1821 and captured several slavers. Lieutenant Stockton also convinced the local African chief to relinquish land around Cape Mesurado about which Liberia grew. Stockton became the commander of the US Navy's first screw-propelled steamer, the "Princeton", in 1843.