The significance of agriculture to Orange County’s history was great enough that the Commonwealth of Virginia set aside approximately in the western portion of the county as the Madison-Barbour Rural Historic District. The District was added to the National Register of Historic Places in 1991 and is the largest such district in Virginia. It includes James Madison’s Montpelier and James Barbour’s Barboursville mansion (designed by Thomas Jefferson, now in ruins). It includes other sites listed on the National Register.