The U.S. Coaling Station was established before the Civil War. The original brick structure, costing about $50,000, is now occupied by offices and as a warehouse; other sheds were completed in 1898 and 1899. The total cost of this part of the navy plant was about $500,000. The office and depot of the 7th Lighthouse District are located at Key West, the office of the Custom-house and the depot and buoy wharf on the water front of the grounds. The district contains 97 lights and 299 buoys.