One of America's wealthiest men, Alfred Irenee DuPont built the palatial French-style mansion in 1909 as a home for himself and his second wife, Alicia. Even though Alfred's social and business relations with the rest of the DuPont family were strained, he looked back with fondness to the ancestors who founded the American dynasty. He named Nemours after a small town in France that his great-great-grandfather, Pierre, represented in the French Estates-General in 1789. Pierre also took the name Nemours when he received his patent of nobility from Louis XVI.
In 1909 Alfred was the vice president and general manager of the DuPont Company, and an heir to the family dynasty founded in 1799 when Pierre Samuel DuPont de Nemours emigrated from France. Pierre and his son, Eleuthere opened a gunpowder works on the Brandywine River in Delaware. By the time Alfred was born in 1864 the family was already extremely wealthy. Along with his financial fortune, Alfred inherited Pierre's scientific aptitude and went on to contribute many innovations to the family business, one being a waterwheel he designed in 1931. Today, it can be seen in the pump house at Nemours.
Alfred's troublesome relationship with the DuPont family began with his takeover of the DuPont Company in 1902 along with his cousins Coleman and Pierre. Four years later, Alfred divorced his first wife and soon outraged the family even more by marrying his cousin, Alicia, in 1907. He showed his love by showering her with gifts, the grandest of which was the spectacular Nemours that he built for her in the late-18th-century French style that she adored. Set on a 3,000-acre plot of land, Alfred also ensured that his new home was thoroughly modern by incorporating the latest technology and many of his own inventions. Nemours was meant to be a private retreat from the rigors of the business world and the turmoil of the DuPont family feud. To maintain this solitude Alfred built a 9-foot wall topped with jagged glass built around the property. Armed guards were stationed at all entry points.
Nemours contained a state-of-the-art solarium, a machine for making 30 lb. blocks of ice, and another for bottling mineral water. An automobile garage in French classical style was built in 1914. Five years later the mansion's staff wing was extended, and a new laundry and French medieval water tower were constructed. Alfred studied architecture in Paris, and in 1929 commissioned his son's new firm to design the elaborate sunken gardens that contain pools, fountains, marble stairways, and open green spaces. They also built a 200 ft. tower designed to hold 31 cast iron bells. The Long Walk extends from the Mansion to the Reflecting Pool and is lined with pin oaks and pink flowering horse chestnuts. The one-acre pool contains 157 jets that can shoot water 12 feet into the air. Around the pool are the Art Nouveau-style, classical mythology-based Four Seasons sculptures.
The dining room hosted many dinner guests. After dinner the ladies would retire to the drawing room while the men enjoyed their cigars and conversations about politics and finance. Portraits in the drawing room include Jessie DuPont, the Duchess of Gloucester, a portrait of "Kitty" Courtenay, and a painting of Marie LeDee DuPont, Alfred's great-great-grandmother.
When Alfred died in 1935 his will created the Nemours Foundation with a mandate to maintain the house and grounds for public enjoyment, and to apply much of his wealth for the care of handicapped children and the indigent elderly. Alfred's third wife, Jessie Ball DuPont had a children's hospital built on the grounds in 1940. Today, it is a world-renowned medieval facility. Jessie lived at Nemours until her death in 1970 and is buried beside Alfred beneath the bell tower. The house and gardens were opened to the public according to his wishes in 1977.