Boone Hall Plantation and Gardens in Mount Pleasant, South Carolina. It is one of America's oldest working plantations, continually growing crops for more than 320 years. Its large Colonial Revival-style plantation house, completed in 1936, replaced the lost original house on the site. The site includes a number of antebellum-era slave cabins or cottages -- later occupied by sharecroppers well into the 20th century -- and an "Avenue of Oaks" of southern live oaks, originally planted in 1743. Photo by Carol Highsmith.