He then resolved to make every exertion in his power to relieve Lord Cornwallis, and in the mean time to act offensively in the north.

An expedition was planned against New London, in Connecticut, and a strong detachment, under the command of General Arnold, was embarked on board a fleet of transports, which landed early in the morning of the 6th of September on both sides the harbour, about three miles from the town.
[Footnote 83: The first indication given by Sir Henry Clinton of suspecting the southern expedition, is in his letter to Lord Cornwallis of the 2nd of September, in which he says, "By intelligence I have this day received, it would seem that Washington is moving southward."] New London is a seaport town on the west side of the Thames.

A fort called fort Trumbull, and a redoubt had been constructed just below it, on the same side of the river; and opposite to it, on Groton hill, was fort Griswold, a strong square fortification, but not fully manned.

General Arnold, who commanded in person the troops that landed on the western side of the harbour, advanced immediately against the posts on that side.

These being untenable, were evacuated on his approach; and he took possession of them with inconsiderable loss.