GW was born at his family's home along Pope's Creek, near where that stream enters the Potomac River, in Westmoreland County, Va.  Since England then used the Julian calendar, GW's actual birthdate was 11 Feb., but it became 22 Feb. when England switched to the Gregorian calendar in 1752. GW was the first child born to Augustine Washington (1694-1743) and his wife, Mary Ball Washington (1708 or 1709-1789), who had married on 6 March 1731. The family included GW's half-brothers, Lawrence (1718-1752) and Augustine (Austin; 1720-1762), and a half-sister, Jane (1722-1735), from Augustine's first marriage to Jane Butler Washington (1699-1729).The household also included a smallish number of black slaves and probably white indentured servants, who assisted in the sturdy, but modest, house and worked the somewhat more than 100 surrounding acres that formed the plantation.