Washington's success at Boston had one good effect. It destroyed Tory influence in that Puritan stronghold. New England was henceforth of a temper wholly revolutionary; and New England tradition holds that what its people think today other Americans think tomorrow. But, in the summer of this year 1776, though no serious foe was visible at any point in the revolted colonies, a menace haunted every one of them. The British had gone away by sea; by sea they would return. On land armies move slowly and visibly; but on the sea a great force may pass out of sight and then suddenly reappear at an unexpected point. This is the haunting terror of sea power. Already the British had destroyed Falmouth, now Portland, Maine, and Norfolk, the principal town in Virginia. Washington had no illusions of security. He was anxious above all for the safety of New York, commanding the vital artery of the Hudson, which must at all costs be defended. Accordingly, in April, he took his army to New York and established there his own headquarters. Even before Washington moved to New York, three great British expeditions were nearing America. One of these we have already seen at Quebec. Another was bound for Charleston, to land there an army and to make the place a rallying center for the numerous but harassed Loyalists of the South. The third and largest of these expeditions was to strike at New York and, by a show of strength, bring the colonists to reason and reconciliation. If mildness failed the British intended to capture New York, sail up the Hudson and cut off New England from the other colonies.