British Gunboats capture French corvette l'Outaouaise during the Battle of the Thousand Islands. The captured ship was renamed HMS Williamson.
Both British and French embarked on a shipbuilding race, but up until 1760 the vessels saw little action and were employed primarily for transportation and dispatch. Some writers have claimed that the French built the Montcalm and the Huron at Fort Frontenac in 1756, but it appears certain that the new ships added to the French fleet were indeed the captured British vessels. However, several gunboats fitted with lugsails and sweeps were constructed there.
In 1758, Lieutenant-Colonel John Broadstreet was directed to raise a force of sailors, soldiers and landsmen in New England and to raid Fort Frontenac. By August 22, they had built sufficient whaleboats and bateaux. With their allies, the Oneida First Nation, they coasted along the south shore, crossed the lake at night and avoided detection until they had taken position only 200 yards from the fort. Broadstreet called on the French to surrender, which they did, and Fort Frontenac fell without a shot being fired. The British also captured nine French ships and all but two were burned. All the stores that could be carried were put into the Montcalm and taken back to Oswego.
The British now occupied both Oswego and Fort Frontenac, and took Niagara in the summer of 1759. Later that year, they launched two schooners, the Johnson and the Murray at Niagara, and, later still, they launched the snow Onondaga. The following year they added the snow Mississaga at Oswego and the snow Mohawk at Niagara.
The French introduced two new vessels to Lake Ontario though they were built at L’Anse a la Construction in the lee of Pointe au Baril, now Maitland, Ontario, located in eastern Ontario along the shore of the St. Lawrence River. On April 9, 1759, a ship-rigged corvette, L'Iroquoise, was launched and on the 12th of the month, a barque, L'Outaouaise. The latter was of the same general size and tonnage as the Montcalm, which had been captured by Broadstreet whereas the L'Iroquoise was slightly smaller. During the summer they put in good service carrying supplies to Fort Niagara but returned to the St. Lawrence to winter. Early in 1760, they were back on Lake Ontario but, as there was no port under French control that they could put in to, they returned to the St. Lawrence once again.
L'Iroquoise ran aground in the St. Lawrence River on August 13, and was no longer fit for service. She went down to lie Royale where she was later captured by the English on August 18 and sunk. The British, with a large flotilla of small boats, came up the St. Lawrence and, near present-day Brockville, did battle with the L’Outaouaise. The sad encounter was not unlike a pack of wolves attacking a large stag. Unfortunately for the French, the big ship was becalmed and thus without hope for escape. At noon, she lowered her fleur-de-lys and surrendered. The British took her over, and renamed her the Williamson. She assisted them in the attack on Fort Levis, lie Royale, where the last shot in the "French-English" war was fired. She served on Lake Ontario until she was lost in a storm in November 1761.
In the 1990s, two divers, Michael Hughes and Dennis McCarthy, identified a wreck as the L’lroquoise. She sits on the bottom in the narrows near the International Bridge, on what is known as Niagara Shoal, between the mainland and Wellesley Island in the St. Lawrence River, where today the bridge crosses from Ontario to New York State. The Mohawk and the Onondaga were lost in 1764, but the details are not known.
This action ended French naval power on Lake Ontario and in the St. Lawrence, however, they still had outposts at Detroit and Mackinac. On September 12, 1760, the famous Roger's Rangers, an independent company of light infantry attached to the British army, set out from Montreal in fifteen small whaleboats. Their objective was to capture Detroit. They travelled up the rapids of the St. Lawrence, along the north shore of Lake Ontario, portaged around Niagara and continued the length of Lake Erie. At the mouth of the Detroit River they met Pontiac, chief of the Ottawa, who had been loyal to the French. At the time he displayed a "peaceful attitude," but later would lead an Indian uprising against the encroachment of the British on Native lands. On November 12, 1760, the Rangers captured the French fort at Detroit. Fort Mackinac, in the Straits of Mackinac, was turned over to the British the following year.