At the head of the most efficient army the United States have possessed during this war, much must be expected of me; and yet I can discern no object which can be achieved at this point worthy of the risk which will attend its attempt." Izard had already predicted that the withdrawal of his forces from Plattsburg would leave northeastern New York at the mercy of the British and he spoke the truth.

No sooner had his divisions started westward than the British army, ten thousand strong, under General Prevost, crossed the frontier and marched rapidly toward the Saranac River and then straight on to Plattsburg.

Possession of this trading town the British particularly desired because through it passed an enormous amount of illicit traffic with Canada.

Both Izard and Prevost agreed in the statement that the British army was almost entirely fed on supplies drawn from New York and Vermont by way of Lake Champlain.

"Two thirds of the army in Canada are supplied with beef by American contractors," wrote Prevost, and there were not enough highways to accommodate the herds of cattle which were driven across the border.
To protect this source of supply by conquering the region was the task assigned the splendid army of British regulars who had fought under Wellington.