Martinsburg is an unincorporated community in Jackson Township, Washington County, in the U.S. state of Indiana. History Martinsburg was founded in 1818 by Dr. Abner Martin, and named for him. A post office was established at Martinsburg in 1830, and remained in operation until it was discontinued in 1919. Geography Martinsburg is located at . References Unincorporated communities in Washington County, Indiana Unincorporated communities in Indiana Louisville metropolitan area Populated places established in 1818 1818 establishments in Indiana