Attacks from the south fell upon the front, or at best upon the flank, of the line of the St.Lawrence.
Attacks from Canada took New York and its dependencies in the rear.
[Illustration] These elements of natural strength, in the military conditions of the North, were impressed upon the minds of the Americans by the prolonged resistance of Canada to the greatly superior numbers of the British Colonists in the previous wars.

Regarded, therefore, as a base for attacks, of a kind with which they were painfully familiar, but to be undergone now under disadvantages of numbers and power never before experienced, it was desirable to gain possession of the St.Lawrence and its posts before they were strengthened and garrisoned.

At this outset of hostilities, the American insurgents, knowing clearly their own minds, possessed the advantage of the initiative over the British government, which still hesitated to use against those whom it styled rebels the preventive measures it would have taken at once against a recognised enemy.
Under these circumstances, in May, 1775, a body of two hundred and seventy Americans, led by Ethan Allen and Benedict Arnold, seized the posts of Ticonderoga and Crown Point, which were inadequately garrisoned.

These are on the upper waters of Lake Champlain, where it is less than a third of a mile wide; Ticonderoga being on a peninsula formed by the lake and the inlet from Lake George, Crown Point on a promontory twelve miles lower down.[1] They were positions of recognised importance, and had been advanced posts of the British in previous wars.

A schooner being found there, Arnold, who had been a seaman, embarked in her and hurried to the foot of the lake.