The Wilkes Street Tunnel was part of the eastern division of the Orange & Alexandria Railroad, founded in 1848 to promote trade with western Virginia. The railroad inaugurated its track in Alexandria on May 7, 1851, with a run from the north end of Union Street to the tunnel, linking the line to warehouses and wharves along the waterfront, while the nearby Smith and Perkins Foundry manufactured locomotives for the Orange & Alexandria and other railroads. The track remained in operation until 1975, when declining industrial activity along the waterfront no longer warranted rail service, and the tunnel became one of Alexandria's few surviving 19th century transportation sites. At the onset of the Civil War, the Orange & Alexandria line was among the Alexandria railroads taken over by Union forces; its northerly section was incorporated into the U.S. Military Railroad, while the track south of the Rappahannock River remained in Confederate hands. Both sections played a major role in Northern and Southern strategy and were a decisive element in the Confederate victory at the Second Battle of Manassas or Bull Run. The tunnel gave the Union army access to the wharves for shipping military supplies on car ferries south to Aquia Creek, terminus of the Richmond, Fredericksburg & Potomac Railroad. Built by cut-and-cover construction through the bluff overlooking the Potomac River and covered to continue the streets above, the tunnel was deepened after World War I to accommodate taller boxcars and runs for a block between Lee and Fairfax Streets before continuing another block to Royal Street as an open cut trench. In 1863, the 54,000 pound locomotive Senator, used by the United States Military Railroad, was photographed about to enter the tunnel; before that service it had been the Thornton of the Concord Railroad and had been built by Amoskeag Locomotive Works of Manchester, New Hampshire, in 1853. Groups of free and formerly-enslaved contraband laborers were employed by the United States Military Railroad to repair tracks damaged by Confederate raids in front of the tunnel. Andrew J. Russell, who enlisted in the Union Army in 1862 with the 141st New York Volunteers before reassignment to the U.S. Military Railroad Construction Corps under General Herman Haupt, documented railroad construction and engineering activities in Alexandria including rail-straightening, prefabricated bridge building, experimental boat construction, and a new technique for transporting railcars by water that was a precursor to the modern intermodal system.
