Henry Algernon du Pont (July 30, 1838 – December 31, 1926) was an American military officer, businessman, and politician from Delaware.

A member of the du Pont family, he graduated first in his class from West Point shortly after the beginning of the American Civil War and served in the U.S. Army, earning the Medal of Honor for his actions during the Battle of Cedar Creek in October 1864.

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, at the outset of the American Civil War.

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.

Du Pont served in General Philip Sheridan's army in the Shenandoah Valley of northern Virginia.

The second brevet was to the rank of lieutenant colonel, dated October 19, 1864, for distinguished service at the Battle of Cedar Creek, Virginia.

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.

The petition centered on whether William T. Watson, the speaker of the Delaware Senate who had ascended to the governorship upon the death of Joshua H. Marvil on April 8, was entitled to cast a vote in the legislature's joint session on May 9.

While the Republican-controlled committee found in du Pont's favor, the Senate as a whole opposed seating him on a party-line vote, with Populists and a Silver Party member joining Democrats, citing a state legislature's right to determine its own membership.

[3] Du Pont was elected to the U.S. Senate on June 13, 1906, to fill the vacancy in the term beginning March 4, 1905.

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.

Citation: Du Pont was portrayed by David Arquette in the 2014 film Field of Lost Shoes, which depicted the Battle of New Market in May 1864.