The garrison, a motley assortment of regulars and militiamen led by Upper Louisiana's lieutenant governor, Captain Fernando de Leyba, suffered a small number of casualties.

The expedition from West Florida never got off the ground because Bernardo de Gálvez, the Governor of Spanish Louisiana, moved rapidly to gain control of Britain's military outposts on the Lower Mississippi and threatened British control over West Florida's principal outposts of Mobile and Pensacola.

[5][6] Patrick Sinclair, the military governor at Fort Michilimackinac, organized the British expeditions from the north in the present-day Michigan.

Beginning in February 1780, he directed Loyalist fur traders to circulate through their territories and recruit interested tribes for an expedition against St. Louis.

[5] Most of the force gathered at Prairie du Chien, where Emanuel Hesse, a former militia captain turned fur trader, took command.

The force numbered about two dozen fur traders and an estimated 750 to 1,000 Indians when it left Prairie du Chien on May 2.

[1] Two hundred Sioux warriors led by Wapasha I made up the largest contingency of the force, with additional sizable companies from the Ojibwe, Menominee, Ho-Chunk, and smaller numbers from other nations.

Leyba was warned by a fur trader in late March 1780 that the British were planning an attack on St. Louis and the nearby American post at Cahokia.

[11] Fort Don Carlos had been constructed earlier in 1767 on the south bank of the Missouri River, near its mouth, just 15 miles north of the village of St.

[16] The next day, Hesse sent Jean-Marie Ducharme and 300 Indians across the river to attack Cahokia, while the remainder arrived around 1:00 pm near St. Louis.

On the first volley, most of the Sauk and Meskwaki fell back, apparently unwilling to fight, leaving many of the other participants suspicious of their motives in joining the expedition and complaining of their "treachery.

[18] A year later, the Spaniards from St. Louis raided Fort St. Joseph and brought the captured British flag back to St.

[20] King Charles III, unaware that he had died, promoted him to the rank of lieutenant colonel because of his valor in action.