Begun in 1804 and embellished over the next two decades, the monumental mansion of Oatlands in Loudoun County, along with its numerous outbuildings and extensive gardens, forms one of the nation’s most elaborate Federal-style country estates. The complex was developed by George Carter, one of the scions of prominent Tidewater families who migrated to Northern Virginia after the Revolution. Carter developed the mansion’s design from illustrations in William Chambers’s A Treatise on Civil Architecture (1786). With its stuccoed walls, demi-octagonal wings, parapeted roof, and a portico of slender Corinthian columns added by Carter in 1827, the house has a special lightness and elegance. The airy rooms with their intricate Federal ornamentation complement the exterior. Oatlands remained in the Carter family until 1897. In 1903 it was acquired by William Corcoran Eustis, grandson of banker and philanthropist William Wilson Corcoran. The estate was donated to the National Trust for Historic Preservation in 1965, and it serves as the centerpiece to the Oatlands Historic District.