Henry Algernon du Pont (1838-1926) was a military officer, a politician from Delaware, and vice president of the E.I. du Pont de Nemours & Co., a chemical company more commonly referred to as the DuPont Company.

Du Pont (1838-1926), son of Henry du Pont (1812-1889) and Louisa (Gerhard) du Pont (1816-1900), was born on July 30, 1838, at Eleutherian Mills, Delaware. After attending the University of Pennsylvania from 1855 to 1856, he enrolled at the U.S. Military Academy at West Point, New York, and graduated at the head of his class in 1861. By 1864, he was a Lieutenant Colonel in the Army. He won a Congressional Medal of Honor for his heroic efforts at the Battle of Cedar Creek during the Civil War.

Du Pont took a one-year leave from the military, beginning in the fall of 1874, and spent the year traveling Europe, with stops in London, Paris, Rome, Lyons, Avignon, Marseilles, Cannes, Nice, Florence, Venice, Genoa, and St. Germain-en-Laye. Following his active military service, du Pont held a variety of positions in companies in the Wilmington, Delaware area: manager of the Wilmington & Kennett Turnpike Company from 1878 to 1919; president and general of Wilmington & Northern Railroad from 1878 to 1926; and began working for the family company, E.I. du Pont de Nemours & Co. in 1878, before being elected vice president in 1899, a position he held until 1902.

On July 15, 1874, du Pont married Mary Pauline Foster (1849-1902) of New York City. Their wedding trip included visits to Niagara Falls, Montreal, and Quebec. The couple had seven children, although only two survived to adulthood: Catherine Barthelemie Paulie du Pont (1875-1876), Louise Evelina du Pont (1877-1958), Antoine Irenee du Pont (1879), Henry Francis du Pont (1880-1969), twins Pierre Irenee du Pont (1882) and Paul Louis du Pont (1882-1883), Anne Victorine Sophie du Pont (1885-1886).

In 1867, his father, Henry du Pont, purchased the Winterthur estate, near Wilmington, Delaware, from James Irenee Bidermann (1817-1890). Henry Algernon and his family moved there in 1876. The mansion and property were remodeled in 1884 and again in 1902. Du Pont inherited the estate in 1889, following his father’s death, and turned management over to his son, Henry Francis, in 1914, who inherited the property upon Henry Algernon’s death in 1926. Henry Francis opened the estate as a museum in 1951.

From 1906 to 1917, du Pont was a U.S. Senator for the state of Delaware. He was a staunch Republican and served on many committees in Washington, DC. He was the author of several military reminiscences and family histories. He was also a farmer and had one of the most valuable private Holstein cattle herds in the United States, which he maintained on his estate, Winterthur.