The Annapolis and Elk Ridge Railroad began service in 1840 between Annapolis and the Washington Branch of the Baltimore & Ohio Railroad at Annapolis Junction. Sponsored by the state, the line was a key route for travel to and from the capital. During the Civil War it was used by Union troops to bypass Baltimore and reinforce Washington after the Baltimore Riot of April 19, 1861. The line served Camp Parole from 1863-1865 and Fort Meade beginning in World War I. It was mostly abandoned by 1935 due to the rise in motor traffic.