Built in 1850, President Street Station in Baltimore, Maryland is a former train station. It is the oldest surviving big city railroad terminal in the United States. Built by the Philadelphia, Wilmington and Baltimore Railroad (PW&B), the station was an important rail transportation link during the Civil War. The station was involved in the Baltimore Riot of 1861, when marching Union troops were attached by an angry mob of Southern sympathizers. The station now serves as Baltimore's Civil War Museum. Patch measures 3 inches by 3 inches.