A party of sailors of the Royal Navy and soldiers from the garrison of Mackinac captured both gunboats by surprise in the first week of September, leaving the British in control of the lake until the end of the war.

When the United States declared war on Britain in 1812, the North West Company put its ships and its voyageurs at the disposal of the British government.

[3] Captain Charles Roberts, commanding the garrison at St. Joseph Island, hastily assembled a force of 47 soldiers from the 10th Royal Veteran Battalion, 3 artillerymen, 180 Nor'Westers who were mostly French-Canadian voyageurs and 400 Native Americans.

During the ensuing winter and spring, the British established another supply line from York to Mackinac, using a former fur trading route via the Toronto portage to Lake Simcoe and then to the Nottawasaga River.

The American force initially consisted of five vessels (the brigs Lawrence, Niagara and Caledonia, and the gunboats Scorpion and Tigress), commanded by Commodore Arthur Sinclair.

In spite of their victory, the British at Mackinac were very short of provisions and would starve if they were not resupplied before Lake Huron froze at the start of winter.

Sinclair had earlier captured a small schooner (Mink) belonging to the Canadian North West Company, and learned from one of the prisoners that the British supply base was at Nottawasaga Bay.

The British detachment at Nottawasaga consisted of a midshipman and 21 sailors of the Royal Navy under Lieutenant Miller Worsley, and 9 French Canadian voyageurs.

Sinclair's orders were that the gunboats were to remain until they were driven from the Lake by bad weather in October, by which time it would be impossible for small boats to re-establish communications between the Nottawasaga and Mackinac.

[9] The Americans had missed one hundred barrels of provisions in a storehouse, and two batteaux and Livingston's large canoe which had been moved higher up the Nottawasaga River toward the depot at Schoonertown.

Worsley removed the obstructions from the river and sailed in open boats for Fort Mackinac with his sailors and Livingston, carrying seventy barrels, late on 18 August.

Accounts of subsequent events vary; some state that Worsley evaded the gunboats, which were forced back into Lake Huron by a storm (which also nearly sank Niagara) a few days later,[10] while others state that one or both gunboats had left the Nottawasaga almost as soon as Niagara was out of sight, hoping to capture boats and canoes involved in the fur trade with their valuable cargoes, and thus leaving the Nottawasaga unguarded.

The Americans then heard that several boats manned by hired Canadian voyageurs under Captain J. M. Lamothe were attempting to reach Mackinac Island with supplies via the French River.

To intercept this party, the gunboats cruised in a narrow channel about 36 miles (58 km) east of Mackinac Island, known as the Detour Passage.

[10] Supplies at Mackinac had run so short that McDouall's soldiers were on half rations, and he had even killed some horses to feed the Native Americans.

Two hundred Ojibwa from Manitoulin Island, led by Chief Assiginack, followed them in nineteen canoes in case any warriors were fighting for the Americans.

The crew of the gunboat (thirty-one sailors and soldiers under Sailing Master Stephen Champlin) spotted them too late, and their fire missed.

At dawn on 6 September, Worsley set sail towards Scorpion in Tigress, under American colours and with most of his men below decks or concealed under their greatcoats.

The end of the war put a halt to most of this construction (although the armed schooner Tecumseth [sic] and the unarmed transport vessel Bee were built in 1816[16] and a naval base was opened at Penetanguishene in 1817).

[17] At the end of the war, some British officers (including McDouall) and Canadians objected to handing back Prairie du Chien and especially Mackinac under the terms of the Treaty of Ghent.

[18] Although small in scale, the British and Ojibwa Indian successes on Lake Huron were vital, given the remoteness and sparse population of the theatre.