 Oatlands Plantation was established by George Carter, a great grandson of Robert "King" Carter, in 1798 on 3,408 acres (1,980 ha) of farmland.It started as a wheat farm, but expanded to include other grains, sheep, a gristmill and a saw mill, and a vineyard.In 1804, Carter began construction of a Federal mansion, which he expanded in the 1820s and 1830s.