With only 94 square miles of land, Mathews is one of the smallest of Virginia's counties. It was originally delineated circa 1651 as Kingston Parish within neighboring Gloucester County. In 1791, the Virginia General Assembly designated it as a separate county and named it for a prominent American Revolutionary War officer, General Thomas Mathews of Norfolk. General Mathews supported the separation legislation and was the Speaker of the Virginia House of Delegates. In 1776, the last of Virginia's Royal Governors, Lord Dunmore, was driven from the colony's shores by Continental cannons at Cricket Hill across from Gwynn's Island. The county has also served as an important shipbuilding center, especially during the 1830s. Captain Sally Louisa Tompkins, the first woman to serve as a commissioned officer in the Confederate Army, was born at Poplar Grove.