Sefton Manor, now called Mill Neck Manor, is a Tudor-Revival mansion that sits on 86 acres on the north shore of Long Island overlooking the Sound in Mill Neck.

William K. Vanderbilt chose architect Richard Morris Hunt to design the 39th birthday present he wanted to give to his wife, Alva. It would be call Marble House and was to be built on Newport’s fashionable Bellevue Avenue. Richard Morris Hunt was the first American educated at the Ecole des Beaux-Arts in Paris.

Rosecliff was commissioned by Nevada silver heiress Theresa “Tessie” Fair Oelrichs and her husband, Hermann, and was built between 1898 and 1902. Flamboyant architect, Sanford White of McKim, Mead & White, designed the house modeled after the Grand Trianon, the garden retreat at Versailles. The mansion is clad in white terracotta adorned with flowers and musical instruments. Jules Allard and Sons of Paris were commissioned to do the interior decoration.

Belcourt was a bachelor pad built for horse enthusiast Oliver Hazard Perry Belmont, with French and Gothic influences, designed by renowned Beaux Arts architect Richard Morris Hunt. The 44,000 square foot house was built with one bedroom and one bathroom and extensive stables and carriage area incorporated into the house’s ground level design.

The Breakers is the grandest of Newport’s summer “cottages” and a symbol of the Vanderbilt family’s social and financial pre-eminence in turn-of-the-century America. The mansion was built for Cornelius Vanderbilt II and his wife Alice, on 13 acres, and is named after the waves that crash at the base of the cliffs. The Italian Renaissance-style mansion replaced a smaller home on the site that was completely destroyed by fire in 1892. Architect Richard Morris Hunt was commissioned to design the house modeled after the 16th century palaces and villas of Genoa. The lavish interiors in the 70-room mansion were the work of Jules Allard & Sons of Paris and Ogden Codman, Jr.

The Elms was the summer residence of Mr. and Mrs. Edward Julius Berwind. In 1898, the Berwin’s engaged Philadelphia architect Horace Trumbauer to design a house modeled after an 18th century French chateau. The mansion was completed in 1901, with interior furnishings designed by Jules Allard and Sons of Paris. Mrs. Berwind died in 1922, and Mr. Berwind invited his sister, Julia, to become his hostess at his Newport house. Mr. Berwind died in 1936 and Julia continued to summer at the house until her death in 1961.

Glenview is a mansion built in 1877 by successful stockbroker, John Bond Trevor. In 1876, Trevor purchased 23 acres and commissioned architect Charles W. Clinton to design his home in the New York City suburbs. Nothing was spared both inside and out, when building the house.

Built between 1908 and 1912, Fonthill Castle was the home of archaeologist, anthropologist, ceramicist, scholar and antiquarian Henry Chapman Mercer. This was his Doylestown, Pennsylvania home and served as a showplace for his famed Moravian tiles that were produced during the Arts & Crafts Movement. The castle was designed by Mercer with an eclectic mix of medieval and gothic architecture styles and an early example of poured reinforced concrete.

Daniel Chester French was one of the most successful artists of the late 19th and the early 20th centuries, producing more than 100 public sculptures. He is best known for his Minute Man in Concord, Massachusetts and the Abraham Lincoln Memorial in Washington, D.C.

In 1895, Frederick W. Vanderbilt purchased the Langdon estate, comprised of 153 acres, a structurally unsound house, a farm and 459 acres on the east side of Post Road. Hyde Park was the name of the stately home he commissioned for himself and his wife, Louise and it was built between 1896 and 1899 on approximately 600 acres. The mansion on a bluff overlooking the Hudson River in Hyde Park, N.Y., this was one of several homes owned by the couple.

Coe Hall is the 65-room centerpiece of the 409-acre Planting Fields Historic State Park located in Oyster Bay, New York. The estate was originally landscaped by Frederick Law Olmsted, featuring greenhouses, rolling lawns, formal gardens, woodland paths and outstanding plant collections.

Westbook Farms started when William Bayard Cutting purchased the George C. Lorillard estate on the Connetiquot River in the Long Island town of Great River. Cutting was a New York City lawyer and sugar beet refiner, who made his fortune in railroads and in the development of the Red Hook, Brooklyn waterfront.

Beauport, also known as the Sleeper-McCann House, was the shingle-style summer home of one of America’s first professional interior designers, Henry Davis Sleeper.

William Gillette was a successful actor and playwright mostly known for his portrayals of Sherlock Holmes on stage. Gillette originated and popularized many common features of the character: the cap and cape, curved pipe, magnifying glass and the phrase “elementary, my dear fellow (which later evolved to “elementary, my dear Watson”. He took his money and ran for the hills overlooking the Connecticut River where he built his 24-room mansion, called the Seventh Sister, on 122 acres.

The 50-acre Sonnenberg Gardens and Mansion State Historic Park is located in Canandaigua, New York. The historic park contains the former summer mansion, a collection of period garden architecture, nine formal and informal gardens, statuary, and a greenhouse complex. The property is a gift to New York State from philanthropists Frederick Ferris and Mary Clark Thompson.

Frederick Gilbert Bourne was a self-made millionaire who resided at the Dakota Apartments in Manhattan and had a 1,000-acre estate in Oakdale, Long Island, called Indian Hall. Bourne became the fifth president of the Singer Sewing Machine Company, which is where the current name “Singer Castle” comes from. While the Bourne’s summered here, they called the castle, “The Towers” and the island, “Dark Island”.

Edith Wharton was part of “Olde New York” society, and is credited with establishing interior design as a profession in the United States. She was the first woman to receive the Pulitzer Prize for non-fiction for her book, Age of Innocence. She believed that good architectural expression included order, scale, and harmony.

George C. Boldt, a millionaire associated with the Waldorf Astoria and the Bellevue-Stratford Hotels in New York City, built this 120-room castle to display his love for his wife, Louise, on picturesque Hart Island, which he re-named Heart Island. Not a single detail or expense was spared in creating the grand castle with tunnels, Italian gardens, playhouse and powerhouse. Construction was ordered to start in 1900 on Heart Island in the Saint Lawrence River, and part of the Thousand Islands.