United States Senator from Delaware
In office June 13, 1906 – March 3, 1917
Preceded by	L. Heisler Ball
Succeeded by	Josiah O. Wolcott
Personal details
Born	July 30, 1838 Greenville, Delaware
Died	December 31, 1926(aged 88) Greenville, Delaware
Political party	Republican
Spouse(s)	Mary Pauline Foster
Children	Henry Francis du Pont Louisa Evelina du Pont
Residence	Greenville, Delaware
Alma mater	University of Pennsylvania United States Military Academy
Occupation	soldier, railroad executive
Religion	Episcopalian
Military service
Allegiance	United States of America Union
Service/branch	United States Army
Years of service	1861 - 1875
Rank	Captain Brevet Lieutenant Colonel
Battles/wars	American Civil War
Awards	Medal of Honor

Henry Algernon du Pont (July 30, 1838 – December 31, 1926) was an American soldier, businessman, and politician from Delaware. A member of the illustrious du Pont family, he graduated from West Point shortly after the beginning of the American Civil War and served in the Union Army, earning the Medal of Honor for his actions during the Battle of Cedar Creek in October 1864.

After retiring from the Army in 1875, he was president of the Wilimington & Northern Railroad Company for 20 years, until 1899. An active member of the Republican Party, he was elected by the state legislature as a U.S. Senator from Delaware, serving most of two terms (June 13, 1906 to March 4, 1917).

Early life and education 
Du Pont was born July 30, 1838 at Eleutherian Mills, near Greenville, Delaware, son of Henry and Louisa Gerhard du Pont and grandson of Eleuthère Irénée du Pont, the founder of E. I. du Pont de Nemours and Company and the family in the United States.

He attended the University of Pennsylvania in Philadelphia, and graduated first in his class from the United States Military Academy at West Point, New York in 1861, after the beginning of the American Civil War.
 
Civil war and military career
Du Pont was commissioned a 2nd Lieutenant of Engineers upon his graduation from West Point on 6 May 1861. Soon after he was promoted to 1st Lieutenant in the 5th Regiment, U.S. Artillery with date of rank of 14 May 1861. He served as a light artillery officer in the Union Army during the war, initially assigned to the defenses of Washington and New York Harbor. From 6 July 1861 to 24 March 1864, he served as regimental adjutant (administrative officer) until he was promoted to captain. He subsequently became chief of artillery in the Army of West Virginia.

Du Pont was part of General Philip Sheridan's army in the Shenandoah Valley of northern Virginia. He received the Medal of Honor for his handling of a retreat at the Battle of Cedar Creek, allowing Sheridan to win a victory in the battle. During the war, du Pont received two brevets (honorary promotions). The first was to the rank of major, dated 19 September 1864, for gallant service in the battles of Opequan and Fisher's Hill. The second brevet was to the rank of lieutenant colonel, dated 19 October 1864, for distinguished service at the Battle of Cedar Creek, Virginia.

After the war, Du Pont continued as a career officer until resigning on 1 March 1875. In the postwar years, he became a companion of the Military Order of the Loyal Legion of the United States (MOLLUS), an organization for former officers of the Union Army and their descendants. Then assigned to Washington, DC, Du Pont was a member of the District of Columbia Commandery and was issued MOLLUS insignia number 10418.

Marriage and family 
At the age of 36, du Pont married Mary Pauline Foster in 1874. They had two children, Henry Francis du Pont and Louisa Evelina du Pont. They lived on his estate, Winterthur, near Greenville, Delaware. The family were members of Christ Episcopal Church in Christiana Hundred.
 
Business career
In 1875 du Pont returned full time to Delaware. Within a few years, he became president and general manager of the Wilmington & Northern Railroad Company, serving from 1879 until 1899. During that time, and for the remainder of his life, he also operated an experimental farm on his estate. Since 1951, when his son established it as a museum, the estate has been operated as the Winterthur Museum and Country Estate near Greenville, Delaware.
 
Political career
Du Pont was elected to the U.S. Senate on June 13, 1906, to fill the vacancy in the term beginning March 4, 1905. During this term, he served with the Republican majority in the 59th, 60th, and 61st U.S. Congress. In the 61st Congress he was Chairman of the Committee on Expenditures in the Military Affairs Department.

He was again elected to the U.S. Senate in 1911. During this term, he served with the Republican majority in the 62nd Congress, but was in the minority in the 63rd, and 64th U.S. Congress. In the 62nd Congress he was again Chairman of the Committee on Expenditures in the War Department, in the 63rd Congress he was a member of the Committee on Military Affairs, and in the 64th Congress he was a member of the Committee on Transportation and Sale of Meat Products.

In the first popular election of a U.S. Senator in Delaware, du Pont lost his bid for a third full term in 1916 to Democrat Josiah O. Wolcott, the Delaware Attorney General. In all, he served most of two terms from June 13, 1906 to March 4, 1917, during the administrations of U.S. Presidents Theodore Roosevelt, William H. Taft and Woodrow Wilson.
 
Death and legacy
Henry A. du Pont died at his home, Winterthur, and is buried in the Du Pont de Nemours Cemetery at Greenville, Delaware. His son, Henry Francis du Pont, developed his home into the well known Winterthur Museum. Archival materials relating to him are part of the Archives owned by the museum at Greenville, near Wilmington.
 
Medal of Honor
Rank and organization: Captain, 5th U.S. Artillery. Place and date: At Cedar Creek, Va., October 19, 1864. Entered service at: Wilmington, Del. Birth: Eleutherean Mills, Del. Date of issue: April 2, 1898.