Antoine Le Moyne de Châteauguay was born on 17 July 1683 in Montreal, French Canada. His parents were Charles Le Moyne, seigneur de Longueil, a soldier, interpreter and merchant, and Catherine Thierry. His father had emigrated from France to Canada in 1640. His father had served in the war with the Iroquois and helped considerably in pacifying New France and defending its frontiers. Antoine Le Moyne was the eleventh and youngest son of Charles Le Moyne, who also had two daughters. Ten of these sons served France with distinction in the colonies, while one died young. The third son, Pierre Le Moyne d'Iberville is perhaps the best known. Antoine Le Moyne succeeded his brother Louis Le Moyne as sieur de Chateauguay when Louis was killed in 1694. He joined the navy as a midshipman.
Louisiana expedition (1698–1702)
Châteauguay accompanied his brother Iberville on an expedition to the lower Mississippi valley that left Brest in 1698 and anchored in Mobile Bay on 31 January 1699. Three others brothers were on this expedition, Joseph Le Moyne de Sérigny, Gabriel Le Moyne d'Assigny, and Jean-Baptiste Le Moyne de Bienville. As leader of the expedition, Iberville is known as the founder of the colony of Louisiana. Châteauguay helped Bienville establish Fort La Boulaye on the lower Mississippi in 1700. In 1702 he was given command of the fort and warehouse on Dauphin Island at the entrance to Mobile Bay. In 1702 Iberville and Bienville founded the city of Mobile, capital of the new colony. Châteauguay was made a captain in Louisiana in 1703.
Later career (1703–47)
Châteauguay married Marie Jeanne Emilie des Fredailles. In a memorial written by Bienville at New Orleans on 25 January 1723 he states that only four of the brothers were still alive: himself, Baron de Longueil, Serigny and Chateauguay. All of them were Knights of the Order of Saint Louis. For a few months in 1725 Châteauguay was governor of Louisiana. He replaced Pierre Sidrac Dugué de Boisbriant, and was in turn replaced by Étienne Boucher Périer de Salvert. In 1727 Châteauguay was appointed king's lieutenant at Fort Saint Pierre in Martinique. He took office as governor of Cayenne on 9 July 1738, replacing the commandant Gilbert Guillouet d'Orvilliers. Châteauguay left for France in June 1743 and d'Orvilliers took over again as head of the colony. Châteauguay was appointed governor of Île Royale in 1745, but died before taking office. He died in Rochefort, Charente-Maritime, on 21 March 1747 at the age of 63. In August 2014 it was reported that a group of cyclists wanted to rename Three Mile Creek in Mobile to Bayou Chateauguay, which they said was the name given to it by the early French colonists after Antoine de Chateauguay.