The Westernmost Battle of the Revolutionary War
When we think of the American Revolutionary War, we tend to focus on the Eastern states—New England, Virginia, and the Carolinas. But territories far beyond that played a critical role as well.
The Battle of St. Louis—fought on May 26, 1780—was the westernmost battle of the American Revolution and proved pivotal to the war’s outcome. It’s sometimes referred to as the Battle of Fort San Carlos.
The Road to St. Louis: International Stakes
To understand this battle, we need some background.
By the mid-18th century, four major powers had interests in North America: Spain, Great Britain, France, and the newly formed American colonies, alongside alliances with many Native American nations.
The French and Indian War (1754–1763) ended with France secretly giving its lands west of the Mississippi to Spain.
In the 1763 Treaty of Paris, France ceded its eastern lands to Britain.
Britain began taxing its 13 Colonies heavily, prompting unrest and rebellion.
The war officially began in April 1775 at Lexington and Concord.
By July 4, 1776, the Colonies declared independence.
France joined the war in 1778, followed by Spain in 1779—transforming it into a global conflict. Spain had already been helping with supplies, weapons, and gunpowder.
George Rogers Clark and British Concerns
George Rogers Clark, a young Virginian, had headed west at 19. Britain claimed the western territories and recruited Native American allies to attack settlers. Clark resisted, forming a militia and later receiving secret orders from Governor Patrick Henry to seize British land.
Clark successfully took control of key territory in southern Illinois and Indiana, including Cahokia.
This alarmed the British. They devised a plan to reclaim the Mississippi River Valley by attacking St. Louis (under Spanish control) and Cahokia (under American control).
Enter Captain Emanuel Hesse
British officer Captain Emanuel Hesse led the western campaign.
He recruited Native Americans from the Great Lakes region, including Sioux, Fox, Chippewa, Winnebago, Wapashaw, and Sauk tribes, with promises of weapons, wealth, and exclusive trading rights.
He was also joined by Canadian fur trappers loyal to Britain.
By April 1780, Hesse’s force—around 1,000 strong—was headed south toward St. Louis.
St. Louis at the Time
In 1780, St. Louis was a modest Spanish village of about 700 people, a mile long and three blocks deep. It was governed by Lieutenant Governor Fernando de Leyva, a strict, unpopular Spanish officer who considered St. Louis immoral and chaotic.
The town was largely unfortified—just small fences around homes. But on March 17, 1780, Leyva received word of an imminent attack, thanks to Lorna Anelay, a trader’s daughter who had overheard Native American plans and paddled 60 miles to warn the town.
Preparing for Battle
Leyva quickly acted:
All men ages 15 to 50 were drafted into a militia.
A limestone watchtower was constructed on the highest point of the village—roughly where Busch Stadium is today.
The tower was named Fort San Carlos, in honor of King Carlos III of Spain. It was 30–40 feet high, and armed with cannons from an old upriver fort.
Defense Strategy:
750 yards of trench dug north of the tower, and 1,250 yards south.
Gates were installed at city entrances.
200 total militiamen, including 65 reinforcements from Ste. Genevieve.
Boats were secured, cannons were loaded, food and water were stocked.
May 25: The Feast of Corpus Christi
British scouts arrived on May 25th—unaware the town had been fortified.
Villagers were out picking strawberries and flowers for the Catholic Feast of Corpus Christi. The scouts couldn’t approach without being spotted.
They retreated, having gained little intelligence, but still planned to attack the next day.
May 26, 1780: The Battle Begins
At 1 p.m., nearly 1,000 attackers—British officers, fur traders, and Native warriors—stormed from the woods, firing bullets and arrows into the commons.
The response:
Church bells rang to alert the militia.
All defenders rushed to their stations.
Women and children were moved to the governor’s house under guard.
The town’s bell, used to signal the start of the battle, still exists today.
Key Moments:
The British tortured captives in the commons, trying to lure defenders into the open.
Leyva refused to take the bait.
The attackers were unorganized and didn’t coordinate.
Upon hearing the first cannon fire, the Sauk and Fox tribes fled, thinking it would be an easy ambush.
Other groups took turns attacking, not fighting together.
A weak spot in the trench was found—but by then, retreat and confusion had spread among the British allies.
Aftermath:
As they fled, they burned crops, livestock, and outbuildings.
St. Louis had won. But Leyva kept the militia on guard, refusing to allow even recovery of bodies until days later.
Casualties and Simultaneous Battles
St. Louis lost 21 people (about 7% of the population), with 7 wounded and 25 captured.
Meanwhile in Cahokia:
British forces attacked the mission compound, where George Rogers Clark had just arrived.
250 militiamen defended the stone mission buildings.
Cahokia’s defenders held the line.
British forces quickly retreated, burning crops and killing livestock as they left.
Casualties: 5 killed, 4 captured, unknown injured.
Retaliation and Continued Defense
A few months later, the Spanish militia from St. Louis and Clark’s men launched a counteroffensive.
They found the Sauk and Fox village empty and burned it to the ground, leaving behind a warning.
Soon after, tribal leaders peacefully surrendered British flags and medals in St. Louis.
To prevent future attacks, an early-warning post system was created and remained in place until at least 1783.
Legacy of Fort San Carlos
By 1818, Fort San Carlos was dismantled.
Today, a plaque stands at Walnut and Broadway, donated in 1946 by the Sons of the Revolution. It reads:
“Near this spot stood Fort St. Carlos erected in 1780. It was attacked May 1780 by the British and Indians and successfully defended by the Spanish garrison under Captain Fernando de Leyva. The victory prevented Great Britain from gaining control of the Mississippi Valley in the later years of the American Revolutionary War.”
Each year, the Commemorative Committee for the Battle of Fort San Carlos holds a tribute, reading aloud the names of the 21 villagers who died in the battle.
Why It Matters
The Battle of St. Louis is considered by some historians to be the most underrated yet critical battle of the war.
It helped determine why St. Louis—and the Midwest—became part of the United States, not Canada or Britain.
It was also the only battle of the war where all five sides fought:
🇪🇸 Spain
🇬🇧 Britain
🇺🇸 The American Colonies
🇫🇷 French Allies
🪶 Native American Nations
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Until next time, I’ll see you in the Lou.