While Burgoyne, with seven thousand regular troops, besides auxiliaries, was moving down to seize the head-waters of the river, fourteen thousand men were removed from its mouth to the Chesapeake.

The eight thousand left in or near New York were consequently tied to the city by the presence of the American army in New Jersey.

This disastrous step was taken in August; in October Burgoyne, isolated and hemmed in, surrendered.

In the following May the English evacuated Philadelphia, and after a painful and perilous march through New Jersey, with Washington's army in close pursuit, regained New York.
This taking of the British fleet to the head of the Chesapeake, coupled with the ascent of the Potomac in 1814 by English sailing-frigates, shows another weak line in the chain of the American colonies; but it was not, like that of the Hudson and Champlain, a line both ends of which rested in the enemy's power,--in Canada on the one hand, on the sea on the other.
As to the sea warfare in general, it is needless to enlarge upon the fact that the colonists could make no head against the fleets of Great Britain, and were consequently forced to abandon the sea to them, resorting only to a cruising warfare, mainly by privateers, for which their seamanship and enterprise well fitted them, and by which they did much injury to English commerce.

By the end of 1778 the English naval historian estimates that American privateers had taken nearly a thousand merchant-ships, valued at nearly L2,000,000; he claims, however, that the losses of the Americans were heavier.