First, however, Amherst sent Brigadier Prideaux to reoccupy Oswego and take Niagara. This done, Prideaux was to descend the St. Lawrence and join Amherst before Montreal. Amherst himself, with the main body of the army, was to advance by way of Lake Champlain and the Richelieu. Montreal taken, the combined forces were to descend to join Wolfe at Quebec. As we shall see, two years were taken in carrying out this comprehensive programme, and the final junction of the British forces was not at Quebec, but before Montreal.
The British Take Niagara.—Prideaux advanced from Albany by way of the Mohawk portage to the mouth of the Oswego, and, leaving Ilaldimand there in command of a strong garrison, proceeded to attack Niagara. Pouchot defended the post with great resolution. The premature bursting of a cohorn killed Prideaux, and Sir William Johnson took command of the besieging force. The British garrison at Pittsburg had been too weak to drive the French from their forts at Venango, Le Beeuf and Presqu'ile, and from these posts a force now set out to relieve Pouchot. This party was met and overcome near Lewiston, and with its defeat all hope of a successful defence was given up by Pouchot, who shortly afterwards surrendered. The posts south of Lake Erie were at once abandoned by their French commandants, who retired to Detroit. This post, with Michillimackinac and the far west, was now completely cut off, and could take no part in the defence of Canada. Fort Rouille, on the north shore of Lake Ontario, was also abandoned by the French and burned. Gage, who superseded Johnson in the command of this left wing of Amherst's army, made no attempt this year to descend the St. Lawrence. He reported that his force was too small to risk the dangers of navigation past La Corne's position.
Amherst's Cautious Advance.—During all this time Amherst was advancing slowly and cautiously toward Montreal at the head of an army of over eleven thousand men. July was nearly over when he reached the outlet of Lake George. Bourlamaque retired before him ; first from Fort Carillon, which the French tried but with only partial success to blow up behind them ; then from Crown Point, after demolishing that fortress ; until, finally, he entrenched himself in a strong position on Isle