George Washington Vanderbilt constructed the opulent Biltmore Estate between 1889-1995 in Asheville, NC. At nearly 179,000 square feet of floor space, the expansive home boasts 250 rooms including a gym, indoor pool, and bowling alley. It remains the largest privately owned home in the United States, and is open to the public for tours.
Standing left to right: Edward Burnett, Richard Morris Hunt, George Washington Vanderbilt (original owner of the Biltmore Estate). Sitting left to right: Frederick Law Olmstead (landscape architect who also designed New York City's Central Park) and Richard Howland Hunt (architect). Details here.
(photographs taken at the Biltmore Estate in Asheville, NC; historical photos are images displayed at the Biltmore Estate.)