While it was funded by the fortunes of a chemical company, Winterthur stands as a paean to handcrafts and horticulture. Jacques Antoine and Evelina du Pont Bidermann moved into this sprawling manse in the Delaware Valley in 1839, named after the Swiss town where Jacques grew up. A relatively modest 12-room Greek revival manor in the Brandywine Valley, it became the homestead of the Du Pont family, expanded over the decades as the family’s business and fortunes multiplied. Its most notable resident and renovator was Henry Francis du Pont, who took responsibility for the estate in 1914 and transformed the estate into a sprawling, 175-room center for his passions: art, agriculture and plants (at its height, 250 staff tended to gardens and livestock spread over 2,500 acres, and the grounds still boasts a fire department, post office, and non-functioning train station). The eclectic Du Pont raised a renowned herd of Holstein cattle (he listed his occupation on tax returns as “farmer”), but also became one of the foremost collectors of American furniture and decorative arts. He collected so much, in fact, that he eventually turned Winterthur into a museum that opened to the public in 1951.

Ironically, James Deering, who derived his fortune from being an executive at the family business, Deering McCormick-International Harvester, considered himself a conservationist, so when he set about designing this palatial winter retreat (called the “Hearst Castle of the East”), he sited the Italian Renaissance villa on the shore to avoid cutting down too many trees. Placed amid 180 acres of mangrove swamp and tropical forest, the property is noteworthy for adapting Mediterranean and European architectural styles to the balmy Florida coast (the name references a northern Spanish province). French and Italian styles are reflected in the garden and façade, designed by Colombian Diego Suarez and F. Burrall Hoffman, respectively. Deering even created his own crest of sorts for the estate, a caravel, a type of Spanish ship. The home reportedly cost $26 million to build in 1916 and employed 1,000 workers. In the '50s, it opened as a museum to the public and can be rented out for public parties. It's also hosted several important political events, including a meeting between President Reagan and Pope John Paul II.

At the largest private residence ever built in the United States, superlatives abound. George Washington Vanderbilt II spared no expense at his 125,000-acre estate in Asheville, North Carolina, which features the work of celebrated architect Richard Morris Hunt and landscape architect Frederick Law Olmsted. Said to be modeled after three historic French chateaus in the Loire Valley, the sprawling estate may appear to be modeled after all of them, since the combined living space inside the numerous buildings totals 178,926 square feet (roughly four acres). Vanderbilt’s 12,000-square-foot stables could hold 20 of his own carriages, in addition to those of guests. To construct the home, a project which lasted from 1889 to 1896, a brick kiln and woodworking factory were built on site. The four-story home, divided into two wings, offers commanding views of the Blue Ridge Mountains as well as a vast collection of incredible statues, artwork and architectural eye candy, including a 70,000-gallon indoor pool, bowling alley, winter garden, 1,700-pound chandelier and a magnificent limestone staircase. Designated a national historic landmark in 1964, it’s currently a major tourist attraction and draws nearly a million visitors annually.

The inspiration for Xanadu in Orson Welles’s classic film Citizen Kane, William Randolph Hearst’s castle in San Simeon was built on family land where he would take camping trips as a child. Architect Julia Morgan designed the ranch and hilltop estate based on the newspaper tycoon’s eclectic tastes, including Spanish themes. "La Cuesta Encantada" ("The Enchanted Hill") became a sprawling enterprise, complete with the nation's largest private zoo, a movie theater, the Neptune Pool (which contained a the façade of a Roman temple Hearst imported from Europe) and a private power plant. A perfectionist, Hearst often ordered different sections to be redesigned and rebuilt; Morgan started pitching ideas in 1915, but the project still was incomplete by the time Hearst died in 1951. Donated by the family to the California state park system, the complex includes a 115-room main building, a series of cottages, and grounds decorated with numerous terraces, staircases and statuary.

It’s revealing that when Cornelius Vanderbilt II set out to build a summer cottage in Rhode Island in 1885, he ended up commisioning a 70-room Italian Renaissance-style palazzo that stands as one of the grandest in a string of extravagant Newport Estates. The Vanderbilt summer home, designed by Richard Morris Hunt, stands as an exemplary Beaux Arts creation, featuring imported marble (including a blue marble fireplace), rare wood and a massive central hall. Hunt used the Renaissance palaces of Genoa as his model for the mansion, which contains a series of open-air terraces looking out at the ocean.

Spanish for Sea-to-Lake, this Palm Beach mansion built between 1924 and 1927 served as the home of Marjorie Merriweather Post, owner of the Post Cereal company and at the time, the wealthiest woman in America. Designed by Marion Sims Wyeth, the 115-room estate between the ocean and Lake Worth offers a fusion of the Moorish and the Mediterranean, including numerous imported tiles and parrot and monkey motifs running throughout the home (seashells and fossils can be found within the stone walls). The home, now known as the Mar-A-Lago Club, is now owned by Donald Trump, and was rented by Michael Jackson and Lisa Marie Presley during their 1994 honeymoon.

One of the largest surviving Gilded Age estates in the Philadelphia area, this formerly grand structure has a much sadder sorry than the others on this list. Though, on the plus side for those looking for a showy new home, it's the only one that is actually on the market. The 110-room Neoclassical Revival mansion, designed by celebrated architect Horace Trumbauer for businessman Peter A. B. Widener at the turn of the century, is currently without an owner, and would require roughly $50 million in repairs to be restored to its former glory. That’s a tall order, since the T-shaped home and estate once housed one the most impressive art collections in America (it had a Raphael room as well as 14 Rembrandts) and contained a luxurious interior, its own electric power plant, a polo field and a private racetrack.

Portland newspaper baron Henry Lewis Pittock (who founded what is now known as The Oregonian) lived inside this French-style chateau set on 46 acres in the hills above Portland. Architect Edward Foulkes designed the residence, completed in 1909, to offer both classic touches, such as ornamental bronzework and polished marble, as well as advanced-for-its-day features including intercoms, a central vacuum system and indirect lighting hidden in alcoves. His wife Georgiana, who loved roses and kept a terraced garden full of them on the estate, helped organize the city’s first Rose Festival.