What is the largest privately owned house in the United States?

The largest privately owned house in the United States is Biltmore Estate in Asheville, North Carolina.

George Washington Vanderbilt II commissioned the mansion, which was designed by architect Richard Morris Hunt and built from 1889 to 1895. Its Châteauesque design was inspired by the grand residences of France, and the completed house contains about 178,000 square feet of floor space.

Biltmore was part of a much larger Vanderbilt estate landscaped by Frederick Law Olmsted, the designer of New York’s Central Park. Vanderbilt opened the house to family and friends on Christmas Eve 1895. The property remains privately owned by Vanderbilt’s descendants through The Biltmore Company.

A common mix-up is confusing the house with the entire estate. “Biltmore Estate” can refer to the mansion, grounds, winery, hotels and other operations, while the record specifically concerns Biltmore House. It is also a private home historically, although it now operates as a major tourist attraction and house museum.