To this surrender the after preservation of Upper Canada, at least, may in a great measure be ascribed, as it caused a delay of nearly a whole year in the meditated invasion,[70] and secured the support of some of the Indian tribes, who were hesitating as to the side they should espouse.
It was the more fortunate that Major-General Brock acted with so much promptitude and vigour, because large reinforcements were on their way to General Hull; and not only would that officer's reverse otherwise have been spared, but the western districts of Upper Canada would probably have fallen before the overwhelming numbers which would soon have been brought against them.
The surrender of Detroit was so unexpected, that it produced an almost electrical effect throughout the Canadas: it was the first enterprize in which the militia had been engaged, and its success not only imparted confidence to that body, but it inspired the timid, fixed the wavering, and awed the disaffected.

Major-General Brock from this moment became the idol of the great mass of those whom he governed; and when he returned to York, whither he arrived on the 27th of August, he was received amidst the heartfelt acclamations of a grateful people, rescued by his promptitude from the ignominy of submitting to a conqueror.

They remembered that in the short space of nineteen days he had, not only met the legislature and settled the public business of the province under the most trying circumstances that a commander could encounter, but, with means incredibly limited, he had gone nearly 300 miles in pursuit of an invading enemy of almost double his own force and compelled him to surrender, thus extending the British dominion without bloodshed over an extent of country almost equal to Upper Canada.[71] The conduct of the American general in so tamely surrendering is inexplicable, as Detroit contained an ample supply of ammunition and provisions for nearly a month, besides an abundance of wheat in the territory, with mills to grind any quantity into flour.

One of his officers, Colonel Cass, in a long letter to the Honorable William Eustis, the secretary of war at Washington, said: "I have been informed by Colonel Findley, who saw the return of the quartermaster-general the day after the surrender, that their whole force, of every description, white, red, and black, was 1,030.[72] They had twenty-nine platoons, twelve in a platoon, of men dressed in uniform.

Many of these were evidently Canadian militia.