The Arnold Farm tract dates to the mid-1750's, when it was laid out by German immigrant Johannis Peter Gaver, who named it "Gaver's Discovery." He built the stone house and improved the property in the 1790's. After passing through the hands of others over the years, the property became home to John and Lydia Biser in the 1820s and 1830s; their household included two enslaved female servants and four free black men who worked the fields. In 1853, David Arnold and his brother, John, purchased the 170-acre parcel and enlarged the main house in the 1870s. Peaceful farm life was thrown into turmoil on September 14, 1862, when Union troops from the 6th Pennsylvania Cavalry, 96th Pennsylvania Infantry, and 2nd and 4th Vermont fought the Confederate 16th Virginia for control of the Arnold land. While the Confederates took position behind the stone wall to the west, Union troops used a barn as shelter. The outnumbered Confederate troops soon retreated up the mountain, resulting in a Union victory. The Arnold family took shelter in their cellar during the fighting. Troops then used the Arnold Farm fields as a campsite for the next six months. Archaeologists from the Maryland Department of Transportation surveyed the property and found evidence of the skirmish and camps. They determined that Union troops approached from the southeast and effectively held the Confederates off until they retreated. Hardware and 19th-century nails in the middle of the field suggest that the barn once used as shelter by the Union troops is no longer standing. The Arnold Farm was a key battle site during the Crampton's Gap engagement in 1862.