Hooff's Run Bridge is one of the last remnants of Alexandria's first railroad, the Orange & Alexandria, commonly called the O&ARR, which opened in 1851 and had 148 miles of track in 1860. Built as part of the line running from Alexandria's Potomac River wharves to the roundhouse at Duke and Wolfe streets and then west to Manassas Junction, Orange, Gordonsville, and Lynchburg, Virginia, the railroad helped make Alexandria a regional commercial center in the mid-nineteenth century. During the Civil War from 1861 to 1865, the U.S. Military Railroads seized the line and used it to transport troops and supplies west and south, while thousands of wounded Union soldiers were brought from battlefields to more than 30 U.S. military hospitals in Alexandria. The Hooff family has maintained a presence in Alexandria since the eighteenth century, with family members involved in farming, butchering, banking, and real estate. The bridge itself has two round arch sections, an older northern portion and a southern addition. Its northern part dates from 1856 and replaced a wooden trestle used from 1851 to 1895 when the Orange & Alexandria Railroad began operation. The 28-foot-wide structure was built with a brick barrel vault, still visible beneath the bridge, and faced with gray dry-laid sandstone. A 16-foot-wide addition was built by the Washington-Southern Railroad circa 1885 to 1895 to carry another track. By the early twentieth century, two more bridges with additional tracks stood to the north, but both were dismantled around 1948. Hooff's Run Bridge is the only existing stone structure associated with the Orange & Alexandria Railroad in the Commonwealth of Virginia, the oldest surviving bridge in Alexandria, and, with the Wilkes Street Tunnel, one of two preserved structures associated with the town's first railroad.
