Bayou Manchac or the Iberville River was the northern boundary of the Spanish Isle of Orleans and provided a water route from the Mississippi east into the Amite River and through Lakes Maurepas, Pontchartrain, and Borgne into the Gulf of Mexico. Pierre Le Moyne, Sieur d'Iberville, used this route when he returned in 1699 from his exploration up the Mississippi to the mouth of the Red River. Because the Treaty of Paris in 1763 left the Isle of Orleans in Spanish hands (ceded by France in 1762), this route was of vital importance as an outlet for British navigation from the upper Mississippi. At the mouth of the Manchac-Iberville stream, on the Mississippi, the British established Fort Bute or Manchac Post in 1763. From then until its capture by Governor Bernardo de Galvez on 7 September 1779, it was an important military and trading post. The Battle of Fort Bute, as it is often called, was the opening salvo in Spain's war on Britain in North America. Even though a hurricane had destroyed much of Galvez's fleet on 15 August, the governor quickly assembled a small army of regulars and Acadian and Spanish militia, and led them on a brutal eleven-day march through the bayou. The Spanish attack caught the garrison completely by surprise, as they were unaware that Spain and Britain were at war.

SEE ALSO Galvez, Bernardo de.

Revised by Michael Bellesiles