The Washington City Canal operated from 1815 until the mid-1850s in Washington, D.C. The canal connected the Anacostia River, termed the "Eastern Branch" at that time, to Tiber Creek, the Potomac River, and later the Chesapeake and Ohio (C&O) Canal. The canal became disused during the late 19th century and the city government covered over or filled in various sections in 1871. The canal's Lockkeeper's House, built in 1837 near the present-day intersection of 17th Street and Constitution Avenue NW, was preserved and is now the second oldest building on the National Mall.