iMajor and Mrs. James H. Dooley transformed rough fields and pastures into a showplace many American millionaires were creating during the Gilded Age.

The Casements, named for the large hand-cut casement-style windows that adorn the mansion, was purchased in 1918 by John Davidson Rockefeller at age 78.

The Federal-style mansion in the Georgetown neighborhood of Washington D.C. was originally the home of Martha Washington’s grandaughter Martha Parke Custis Peter and her husband, Thomas.

Marjorie Merriweather Post was a pioneering business executive, engaged citizen, generous philanthropist, distinguished collector and amazing party hostess.

The Cairnwood Mansion is an L-shaped, Beau Arts gem designed by Carrere and Hastings nestled in the serene countryside. The 26,000 square-foot, 28-room mansion was built in 1895 for John Pitcairn, Jr,

James Deering, socialite and antiquities collector built an elaborate Florida villa and estate named Vizcaya on Biscayne Bay in Miami.

Biltmore, the opulent 250-room French Renaissance chateau, nestled in North Carolina’s Blue Ridge Mountains, was the vision of George Washington Vanderbilt, carried out by renowned architect Richard Morris Hunt. Construction began in 1889 and the opulent estate, with grounds designed by Frederick Law Olmsted, was opened on Christmas Eve in 1895 to family and friends.

Boscobel is a historic house museum located in Garrison, New York. It was built between 1804 and 1808 as the dream house of wealthy Loyalist, States Morris Dyckman in Montrose, New York.

In 1924, one of America’s wealthiest couples, started building a fifty-five room, 36,000 square-foot mansion called Ca’ d’Zan (meaning House of John) on Sarasota Bay in Florida.

Eagles Nest is the Spanish Revival 24-room mansion on an estate in Centerport, NY overlooking Northport Harbor. The house was commissioned by William K. Vanderbilt II and designed by Warren and Wetmore.

Crane created this lavish summer retreat for his wife, Florence Higinbotham Crane and three children, Cornelius and Florence. The Crane Estate would come to exemplify the American Country Place Era, which emphasized the integration of indoor and outdoor spaces.

Monticello was the home of Declaration of Independence author, architect, Governor of Virginia, Ambassador to France, U.S. Vice President, two-term President and Founding Father Thomas Jefferson. Jefferson called Monticello his home from 1770 until his death in 1826.

Gabriel Manigault designed this house for his brother, to reflect his wealthy lifestyle. The Manigault family owned several plantations, and hundreds of slaves.

Tucked away along the banks of the Hudson River is Washington Irving’s charming home called Sunnyside.

Clermont was the Hudson River seat of New York’s politically and socially prominent Livingston Family.

This brick, Georgian-style mansion reflects the pre-Revolutionary War wealth and status of Fredericksburg merchant, Fielding Lewis. Fielding was married to Betty Washington, George Washington’s sister.

Franklin W. Smith built his winter home, Villa Zorayda, in St. Augustine in 1883. He was inspired by the Alhambra Palace in Granada, Spain.

This house was built on Meeting Street in 1808 for wealthy merchant and slave trader Nathaniel Russell.

It is hard to believe that a man who was rescued and taken care of by slaves, managed to become a slave trader, buying and selling people like property. The Sorrel family lived here until 1859 when it was sold it to a Connecticut businessman named Henry Weed.

Opened to the public in 1954, the property allows visitors to explore the complicated relationships between the most and least powerful people in the city of Savannah in the early 19th century.