The Americans now stood with their backs to a swift tidal stream, nearly a mile wide, with only a feeble line of works between them and an enemy more than double their number.
On the morning of the 27th, Sir Peter Parker, with a 64-gun ship, two 50's, and two frigates, attempted to work up to New York, with a view of supporting the left flank of the army; but the wind came out from the north, and, the ebb-tide making, the ships got no nearer than three miles from the city.

Fortunately for the Americans, they either could not or would not go farther on the following two days.
After dark of the 28th, Howe broke ground for regular approaches.
Washington, seeing this, and knowing that there could be but one result to a siege under his condition of inferiority, resolved to withdraw.

During the night of the 29th ten thousand men silently quitted their positions, embarked, and crossed to Manhattan Island, carrying with them all their belongings, arms, and ammunition.

The enemy's trenches were but six hundred yards distant, yet no suspicion was aroused, nor did a single deserter give treacherous warning.

The night was clear and moonlit, although a heavy fog towards daybreak prolonged the period of secrecy which shrouded the retreat.