An expedition, in 1756, against Fort Oswego, on the right bank of Lake Ontario, was completely successful; General Webb had no time to relieve the garrison, which capitulated.

Bands of Canadians and Indians laid waste Pennsylvania, Maryland, and Virginia.

Montcalm wrote to the minister of war, Rouille, "It is the first time that, with three thousand men and less artillery, a siege has been maintained against eighteen hundred, who could be readily relieved by two thousand, and who could oppose our landing, having the naval superiority on Lake Ontario.

The success has been beyond all expectation.

The conduct I adopted on this occasion and the arrangements I ordered are so contrary to the regular rules, that the boldness displayed in this enterprise must look like rashness in Europe.
Therefore, I do beseech you, monseigneur, as the only favor I ask, to assure his Majesty that, if ever he should be pleased, as I hope, to employ me in his own armies, I will behave differently." The same success everywhere attended the arms of the Marquis of Montcalm.
In 1757 he made himself master of Fort William Henry, which commanded the lake of Saint-Sacrement; in 1758 he repulsed with less than four thousand men the attack of General Abercrombie, at the head of sixteen thousand men, on Carillon, and forced the latter to relinquish the shores of Lake Champlain.