The Federal Arsenal at Harpers Ferry

In 1796, the federal government purchased a 125-acre (0.5 km²) parcel of land from the heirs of Robert Harper and, in 1799, construction began on the United States Armory and Arsenal at Harpers Ferry. This was one of only two such facilities in these United States, the other being Springfield, Massachusetts, and between them they produced most of the small arms for the US Army. The town was transformed into an industrial center: Between 1801 and its partial destruction in 1861 to prevent its capture during the Civil War, the Armory produced more than 600,000 muskets, rifles, and pistols. Inventor Captain John H. Hall pioneered the use of interchangeable parts in firearms manufactured at his Rifle Works at the armory between 1820 and 1840; his M1819 Hall rifle was the first breech loading weapon adopted by the US Army.

This industrialization continued in when the Chesapeake & Ohio Canal reached Harpers Ferry linking it with Washington, D.C. A year later, the Baltimore & Ohio Railroad began train service through the town.