Harpers Ferry is a historic town in Jefferson County, West Virginia. In many books the town is called "Harper's Ferry" with an apostrophe. It is situated at the point of the Potomac and Shenandoah rivers where the U.S. states of Maryland, Virginia and West Virginia meet. The town is located on a low-lying flood plain created by the two rivers and surrounded by higher ground. Historically, Harpers Ferry is best known for John Brown's raid on the Armory in 1859 and its role in the American Civil War. As of the 2000 census, the town had a population of 307. The lower part of Harpers Ferry is located within Harpers Ferry National Historical Park. Most of the remainder, which includes the higher more populated area, is included in the separate Harpers Ferry Historic District. Two other National Register of Historic Places properties adjoin the town: the B & O Railroad Potomac River Crossing and St. Peter's Roman Catholic Church. The Appalachian Trail Conservancy (ATC) headquarters is located in Harpers Ferry and the town is one of only a few that the Appalachian Trail passes directly through.