War of 1812: Siege of Detroit

Brigadier General William Hull (circa 1800). Photograph Courtesy of the National Park Service

The Siege of Detroit took place August 15-16, 1812, during the War of 1812 (1812-1815) and was one of the opening actions of the conflict. Beginning in July 1812, Brigadier General William Hull conducted an abortive invasion of Canada before withdrawing back to his base at Fort Detroit. Lacking in confidence despite superior numbers, Hull was soon besieged by a smaller British and Native American force led by Major General Isaac Brock and Tecumseh. Through a mix of intimidation and deception, Brock and Tecumseh were able to compel Hull's surrender of over 2,000 men while only having two men wounded. A humiliating defeat for the Americans, Fort Detroit would remain in British hands for over a year.


As war clouds began to gather in the early months of 1812, President James Madison was encouraged by several of his key advisors, including Secretary of War William Eustis, to begin making preparations to defend the northwest frontier. Overseen by the Governor of the Michigan Territory, William Hull, the region possessed few regular troops to defend against a British invasion or attacks by Native American tribes in the area. Taking action, Madison directed that an army be formed and that it move to reinforce the key outpost of Fort Detroit.

Hull Takes Command

Though he initially refused, Hull, a veteran of the American Revolution, was given command of this force with the rank of brigadier general. Traveling south, he arrived at Dayton, OH on May 25 to take command of three regiments of Ohio militia led by Colonels Lewis Cass, Duncan McArthur, and James Findlay. Slowly moving north, they were joined by Lieutenant Colonel James Miller's 4th US Infantry at Urbana, OH. Moving across Black Swamp, he received a letter from Eustis on June 26. Carried by a courier and dated June 18, it implored Hull to reach Detroit as war was imminent.

A second letter from Eustis, also dated June 18, informed the American commander that war had been declared. Sent by regular mail, this letter did not reach Hull until July 2. Frustrated by his slow progress, Hull reached the mouth of the Maumee River on July 1. Eager to speed the advance, he hired the schooner Cuyahoga and embarked his dispatches, personal correspondence, medical supplies, and sick. Unfortunately for Hull, the British in Upper Canada were aware that a state of war existed. As a result, Cuyahoga was captured off Fort Malden by HMS General Hunter the next day as it attempted to enter the Detroit River.

Siege of Detroit

  • Conflict: War of 1812 (1812-1815)
  • Dates: August 15-16, 1812
  • Armies and Commanders
  • United States
  • Brigadier General William Hull
  • 582 regulars, 1,600 militia
  • Britain and Native Americans
  • Major General Isaac Brock
  • Tecumseh
  • 330 regulars, 400 militia, 600 Native Americans
  • Casualties
  • United States: 7 killed, 2,493 captured
  • Britain and Native Americans: 2 wounded

The American Offensive

Reaching Detroit on July 5, Hull was reinforced by around 140 Michigan militia bringing his total force to around 2,200 men. Though short on food, Hull was directed by Eustis to cross the river and move against Fort Malden and Amherstburg. Advancing on July 12, Hull's offensive was hampered by some of his militia who refused to serve outside of the United States.

As a result, he halted on the east bank despite the fact that Colonel Henry Proctor, commanding at Fort Malden, had a garrison numbering only 300 regulars and 400 Native Americans. As Hull was taking tentative steps to invade Canada, a mixed force of Native Americans and Canadian fur traders surprised the American garrison at Fort Mackinac on July 17. Learning of this, Hull became increasing hesitant as he believed large numbers of Native American warriors would descend from the north.

Though he had decided to attack Fort Malden on August 6, his resolve wavered and he ordered American forces back across the river two days later. He was further concerned about dwindling provisions as his supply lines south of Detroit were under attack by British and Native American forces.

Major General Sir Isaac Brock. Photograph Source: Public Domain

The British Respond

While Hull spent the early days of August unsuccessfully attempting to re-open his supply lines, British reinforcements were reaching Fort Malden. Possessing naval control of Lake Erie, Major General Isaac Brock, the commander for Upper Canada, was able to shift troops west from the Niagara frontier. Arriving at Amherstburg on August 13, Brock met with the noted Shawnee leader Tecumseh and the two rapidly formed a strong rapport.

Possessing around 730 regulars and militia as well as Tecumseh's 600 warriors, Brock's army remained smaller than his opponent. To offset this advantage, Brock combed through the captured documents and dispatches that had been taken aboard Cuyahoga as well as during engagements south of Detroit.

Possessing a detailed understanding of the size and condition of Hull's army, Brock also learned that its morale was low and that Hull was deeply afraid of Native American attack. Playing on this fear, he drafted a letter requesting that no more Native Americans be sent to Amherstburg and stating that he had over 5,000 on hand. This letter was intentionally allowed to fall into American hands.

Shawnee leader Tecumseh. Public Domain

Deception Wins the Day

Shortly thereafter, Brock sent Hull a letter demanding his surrender and stating:

The force at my disposal authorizes me to require of you the immediate surrender of Fort Detroit. It is far from my intention to join in a war of extermination, but you must be aware, that the numerous body of Indians who have attached themselves to my troops, will be beyond control the moment the contest commences…

Continuing the series of deceptions, Brock ordered extra uniforms belonging to 41st Regiment to be given to the militia to make his force appear to have more regulars. Other ruses were conducted to deceive the Americans as to the actual size of the British army. Soldiers were instructed to light individual campfires and several marches were conducted to make British force appear larger.

These efforts worked to undermine Hull's already weakening confidence. On August 15, Brock commenced a bombardment of Fort Detroit from batteries on the east bank of the river. The next day, Brock and Tecumseh crossed the river with the intention of blocking the American supply lines and laying siege to the fort. Brock was forced to change these plans immediately as Hull had dispatched MacArthur and Cass with 400 men to re-open communications to the south.

Rather than be caught between this force and the fort, Brock moved to assault Fort Detroit from the west. As his men moved, Tecumseh repeatedly marched his warriors through a gap in the forest as they emitted loud war cries. This movement led the Americans to believe that the number of warriors present was much higher than in actuality. As the British approached, a ball from one of the batteries hit the officer's mess in Fort Detroit inflicting casualties. Already badly unnerved by the situation and fearing a massacre at the hands of Tecumseh's men, Hull broke, and against the wishes of his officers, ordered a white flag hoisted and began surrender negotiations.


In the Siege of Detroit, Hull lost seven killed and 2,493 captured. In capitulating, he also surrendered MacArthur and Cass' men as well as an approaching supply train. While the militia were paroled and permitted to depart, the American regulars were taken to Quebec as prisoners. In the course of the action, Brock's command suffered two wounded. An embarrassing defeat, the loss of Detroit saw the situation in the Northwest radically transformed and quickly dashed American hopes of a triumphant march into Canada.

Fort Detroit remained in British hands for over a year until being re-taken by Major General William Henry Harrison in the fall of 1813 following Commodore Oliver Hazard Perry's victory at the Battle of Lake Erie. Hailed as a hero, Brock's glory proved brief as he was killed at the Battle of Queenston Heights on October 13, 1812.

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Hickman, Kennedy. "War of 1812: Siege of Detroit." ThoughtCo, Aug. 28, 2020, thoughtco.com/war-of-1812-siege-of-detroit-2361363. Hickman, Kennedy. (2020, August 28). War of 1812: Siege of Detroit. Retrieved from https://www.thoughtco.com/war-of-1812-siege-of-detroit-2361363 Hickman, Kennedy. "War of 1812: Siege of Detroit." ThoughtCo. https://www.thoughtco.com/war-of-1812-siege-of-detroit-2361363 (accessed February 3, 2023).