The U.S. Army Corps of Topographical Engineers, authorized on 4 July 1838, consisted only of officers and was used for mapping and the design and construction of federal civil works such as lighthouses and other coastal fortifications and navigational routes. It included such officers as George Meade, John C. Frémont and Stephen Long. It was merged with the United States Army Corps of Engineers on 31 March 1863, at which point the Corps of Engineers also assumed the Lakes Survey District mission for the Great Lakes. In the mid-19th century, Corps of Engineers' officers ran Lighthouse Districts in tandem with U.S. Naval officers.