3. The Breakers
Clearly, the largest privately owned home in the United States was not enough property for the Vanderbilt family, one of the wealthiest families in the Gilded Age of unchecked American prosperity. Cornelius Vanderbilt II, another major scion of the family, had The Breakers, a Newport, Rhode Island summer home, built between 1893 and 1895.
Famed architect Richard Morris Hunt created the Breakers. The property had over 120,000 square feet of livable space. It was designed in the Italian Renaissance aesthetic. The famed Parisian design house of Jules Allard and Sons decorated the interior of the mansion.