William Wadsworth (1765 in Durham, Connecticut – 15 February 1833 in Geneseo, New York) was an officer in the New York State militia, before and during the War of 1812. As a Brigadier General, he commanded the New York militia contingent in the American army at the Battle of Queenston Heights. He waived his right to command over Lieutenant Colonel Winfield Scott, of the United States Army. During the battle, he faced the enemy at all times so that he would not be shot in the back and thus appear to be cowardly. Waving his sword and swearing at the troops back across the river, hoping to instill the fighting spirit in them, Wadsworth made a genuine but vain attempt to get the militia to cross and reinforce their position.
At the end of the battle, Wadsworth was taken prisoner when the American force, cut off on the Canadian side of the Niagara River, surrendered to avoid a massacre by Indians under John Brant attached to the British force.
William Wadsworth was a scion of the prominent Wadsworth family of Connecticut. He was a sixth generation descendant of William Wadsworth (1595–1675) who was one of the Founders of Hartford, Connecticut. In 1790, with his charismatic brother James Wadsworth, they moved from Connecticut to the Genesee Valley of Western New York State.
Settling in "Big Tree" on June 9, 1790, on the east bank of the Genesee River, William and his brother were the leading pioneers of this unsettled region, and ultimately became one of the largest wealthiest land holders of the area. As the settlement in the area increased, William was elected Town supervisor for 21 years. Before and during his tenure, William created and took charge of the area's local militia and eventually took command of the Genesee Valley militia. By the time hostilities broke out between the U.S. and Great Britain in 1812, William Wadsworth was promoted to Brigadier General.