The siege of Detroit, also known as the surrender of Detroit or the Battle of Fort Detroit, was an early engagement in the War of 1812. A British force under Major General Isaac Brock in cooperation with Indigenous warriors under Shawnee leader Tecumseh used bluff and deception to intimidate American Brigadier General William Hull into surrendering the fort and town of Detroit, the Michigan Territory, and his army which actually outnumbered the victorious British and Indigenous warriors.
The British victory reinvigorated the militia and civilian population of Upper Canada, who had previously been pessimistic and affected by pro-American agitators. Many Indigenous tribes in the Old Northwest were inspired to take up arms against the Americans. The British held Detroit for more than a year before their naval squadron on Lake Erie was defeated at the Battle of Lake Erie which forced them to abandon the western frontier of Upper Canada.
Background
American plans and moves
As tensions between the United Kingdom and the United States grew in the early months of 1812, William Hull, the governor of the Michigan Territory, urged President James Madison and Secretary of War William Eustis to "rapidly and sharply reinforce" Detroit which would secure the Old Northwest against Indigenous tribes who were being incited by British agents to attack frontier settlements. Detroit, founded by the French in 1701, was home to about 700 people who occupied 160 houses surrounded by a palisade. Fort Detroit, built by the British during the American Revolutionary War, was located on high ground above the town but had only a small garrison. It was suggested that should war be declared, an army from Detroit might cross the Detroit River and occupy the Western District of Upper Canada, where support could be expected from recent immigrants from the United States who had been attracted by the offer of generous land grants.
Madison and Eustis concurred with this plan and offered command to Hull, an aging veteran of the Revolutionary War. Hull was reluctant to take the appointment, but no other officer with his prestige and experience was available. He accepted after repeated pleas from Madison and was commissioned as a brigadier general in the United States Army. His army initially consisted of three regiments of Ohio militia under Colonels Lewis Cass, Duncan McArthur, and James Findlay. Hull took command of his army at Dayton, Ohio on 25 May but found that they were poorly equipped and ill-disciplined, and no arrangements had been made to supply them on the march. He made hasty efforts to remedy the deficiencies in equipment.
At Urbana, Ohio, Hull was joined by the 4th Infantry Regiment, commanded by Lieutenant Colonel James Miller. From Urbana, Hull forged a new road to Detroit across the Great Black Swamp of northwest Ohio. On 26 June he received a letter from Eustis, dated 18 June, warning him that war was imminent and urging that he should make for Detroit "with all possible expedition." His draft horses were worn out by the arduous march, so when he reached the mouth of the Maumee River, he put his entrenching tools, medical supplies, officers' baggage, despatches, some sick men and the army's band aboard the schooner Cayahoga, to be transported across Lake Erie.
Hull was unaware that the same day Eustis has written his letter, Congress had passed a declaration of war against the United Kingdom. A second letter with this vital information did not reach Hull until 2 July. In Upper Canada, Major General Brock received the news of the declaration on June 26 and immediately sent word to Amherstburg at the mouth of the Detroit River, and to the British outpost at St. Joseph Island on Lake Huron. On 2 July, the unsuspecting Cayahoga was captured near the mouth of the Detroit River by HMS General Hunter, a Provincial Marine brig under Lieutenant Frédérick Rolette.
When Hull reached Detroit on 5 July, he was reinforced by detachments of the Michigan Territory Militia, including the 140 men of the Michigan Legionary Corps, which Hull had established in 1805. The Americans, however, were short of supplies, especially food, as Detroit's inhabitants could provide only soap and whisky. Nevertheless, Eustis urged Hull to cross the river and capture Amherstburg. The fort there was defended by about 300 British regulars, mainly from the 41st Regiment of Foot but including 50 from the Royal Newfoundland Fencible Regiment, roughly 400 Indigenous warriors, and a detachment of the Essex militia. The post's commander was Lieutenant Colonel Thomas St. George, who was later replaced by Colonel Henry Procter of the 41st Regiment. Hull was not enthusiastic and wrote to Eustis that "the British command the water and the savages." Nevertheless, Hull crossed into Upper Canada on 12 July and occupied Sandwich (now Windsor). He issued proclamations which were intended to induce the inhabitants to join or support his army while some of his mounted troops raided up the Thames River as far as Moraviantown. These moves discouraged many of the militia from opposing his invasion, but few actively aided him, even those who had recently moved from the United States.
There were several indecisive skirmishes with British pickets along the Canard River north of Amherstburg. Hull decided that he could not attack the British fort without artillery, which could not be brought forward because the carriages had decayed and needed repair.
British moves
On 17 July, a mixed force of British regulars, Canadian fur traders, and Indigenous warriors captured the important trading post of Mackinac Island on Lake Huron from its small American garrison who were not aware that war had been declared. Many of the Indigenous warriors who had taken part in the attack either remained at Mackinac or returned to their homes, but 100 or more Sioux, Menominee, and Winnebago moved south from Mackinac to join those already at Amherstburg. The news of the capture of Mackinac induced the previously neutral Wyandot living near Detroit to become increasingly hostile to the Americans. Hull learned of the capture of Mackinac on 3 August, when the paroled American garrison reached Detroit by schooner. He feared that this had "opened the northern hive of Indians."
Hull's supply lines ran for 60 miles (97 km) along the Detroit River and the shore of Lake Erie, which was controlled by the Provincial Marine, making them vulnerable to British and Indigenous raiders. A war party under Tecumseh ambushed and routed an American detachment under Major Thomas Van Horne on 4 August at the Battle of Brownstown, capturing more of Hull's despatches. Hull sent a larger party under Lieutenant Colonel Miller to clear his lines of communication and escort a supply convoy of 300 head of cattle and 70 pack horses loaded with flour, which was waiting at Frenchtown. Miller forced a British and Indigenous force under Major Adam Muir of the 41st Regiment of Foot to retreat during the Battle of Maguaga on 9 August. Miller declined to press the attack which allowed the British to withdraw back across the river to Amherstburg. Miller was ill and his losses in the engagement were heavier than those of the British. He remained encamped near the battlefield until Hull ordered him to return to Detroit on 11 Aug.
Hull had begun withdrawing his forces back across the river on August 8. Several of his officers disagreed with the withdrawal and secretly discussed removing him from command. Hull had been quarrelling with his militia colonels since taking command, and he felt that he did not have their support in the field or at their councils of war.
Meanwhile, British Major General Isaac Brock was in York, the provincial capital, dealing with the recalcitrant Legislative Assembly and mobilizing the province's militia. He had at his disposal only a single regiment of regulars and some small detachments of veterans and artillery to support the militia. Brock was aware that there was no immediate threat from the disorganized and badly supplied American forces on the Niagara River, or from the lethargic American commander-in-chief, Major General Henry Dearborn at Albany, New York. Hull alone was occupying or threatening Canadian territory. After finally obtaining support from the Assembly for his measures to defend Upper Canada, Brock (acting under his authority as the lieutenant governor of the province) prorogued parliament and set out on 6 August for Fort Amherstburg with 50 regulars of the 41st Foot and 150 volunteers from the York Militia (the "York Volunteers"). He was later joined by detachments of the Lincoln, Oxford, and Norfolk militias, and by John Norton with 60 warriors from the Six Nations of the Grand River. Travelling in boats along the north shore of Lake Erie in inclement weather, Brock reached Fort Amherstburg on 13 August.
Upon his arrival Brock quickly established a rapport with Tecumseh, ensuring that the Shawnee chief would cooperate with his plans. Tecumseh is said to have turned to his warriors and proclaimed, "Here is a man!" In a subsequent letter Brock wrote that "a more sagacious and a more gallant Warrior does not I believe exist." Brock learned from captured dispatches and letters that Hull's army suffered from a lack of supplies, that morale was low, and that they feared the Indigenous warriors who were allied with the British. Against the advice of most of his subordinates, Brock decided that immediate attack on Detroit was warranted.
Battle
On 15 August, Brock sent his aide-de-camp, Captain John Glegg, under a flag of truce to Fort Detroit with a letter demanding Hull's immediate surrender. In the letter, Brock warned that he would not be able to restrain his Indigenous allies once the attack started:
It is far from my inclination 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 my control the moment the contest commences.
Hull refused, replying, "I am prepared to meet any force which may be at your disposal...”
A few days earlier, after Hull had withdrawn back across the Detroit River, Colonel Procter had ordered the construction of a battery at Sandwich opposite Detroit and on the grounds of the François Baby House, formerly Hull's headquarters. The battery consisted of one 18-pounder, two 12-pounders and two 5½-inch mortars manned by gunners from the Provincial Marine. Brock ordered the artillery to open fire once Glegg returned with Hull's reply. Hull's artillery returned fire without effect, and the guns of both sides fell silent as darkness fell. Tecumseh and about 600 warriors, accompanied by British Indian Department officers, crossed the river that night. Shortly after sunrise, Brock crossed without opposition a few miles downriver of Detroit. With him were 250 men of the 41st Foot, 50 from the Royal Newfoundland Regiment, 30 from the Royal Artillery with five field guns, and 400 militia. Brigade Major Thomas Evans had suggested that Brock have the militia wear cast-off red tunics supplied by the regulars, making it appear from a distance as if his force consisted entirely of professional soldiers. The artillery at Sandwich resumed their bombardment as Brock crossed the river, joined by the guns of the Provincial Marine warships HMS General Hunter and HMS Queen Charlotte.
Brock's original intent was to occupy a position astride the American supply line and wait for the bombardment and a shortage of food to force the Americans to either surrender or come out to fight. He was aware that a day earlier, Hull had sent a detachment of 400 men led by Cass and McArthur to escort a supply convoy to Detroit. Although Hull sent messengers to recall the detachment, Cass and McArthur ignored the order. Tecumseh informed Brock that the detachment was encamped about three miles to the south. To avoid the possibility of being caught between two enemy forces, Brock advanced immediately against the fort. The British column proceeded up the road along the river towards the town before turning inland. The column passed through a field and orchard before forming a line facing the west side of the fort. Meanwhile, Tecumseh's warriors moved through the woods to the north of the fort giving the impression of much larger numbers. In his later report to the Secretary of War, Hull wrote: "The bands of savages which had then joined the British forces, were numerous beyond any former example."