The earliest known inhabitants of what is now Randolph were the Lenni Lenape Native Americans. The earliest European settlers of what is now Randolph were Quakers and one of the pioneering landowners was Hartshorne Fitz-Randolph, who purchased of what would become the township in the Mine Hill area in 1753, later becoming the namesake of the township. New Jersey's first iron mine was established in Randolph in 1713, and for hundreds of years the mines fostered the development of the township, providing the raw materials for weapons used by the Continental Army during the American Revolutionary War. During the war, the area was a supply point for George Washington's army during their winter encampment in nearby Jockey Hollow.