The Berkeley County Riflemen were organized June 10, 1775, at Morgan's Spring, Berkeley County (now Jefferson County), by Capt. Hugh Stephenson of Shepherdstown, in response to a call for Revolutionary War soldiers by Gen. George Washington. These 100 volunteers, dressed in linsey-woolsey hunting shirts, leather leggings, and moccasins, were among the first Southern soldiers to go to the aid of Boston, then under attack from the British. Each man supplied his own uniform, weapon, equipment, and food. On July 17, the troop set out on horseback for Boston, making its famous Bee Line March of 600 miles in 24 days. Captain Stephenson reported to General Washington, who knew several of the men and welcomed them all, that they were "from the right bank of the Potomac."

Capt. Daniel Morgan, who once lived in Berkeley County, organized a troop of volunteers at nearby Winchester, Virginia. These soldiers, sometimes confused or combined with the Berkeley County Riflemen, were known as Morgan's Riflemen. They left Winchester on July 15 and rushed on ahead despite an apparent agreement that the two companies would travel together. Morgan's Riflemen arrived in Boston five days before the Berkeley County group.