Plans for defence.
It being fully decided upon that New York should be held, two entirely distinct sets of measures were found indispensable. First the city was commanded by Brooklyn Heights, rising at short cannon-shot across the East River. These heights were now being strongly fortified on the water-side against the enemy's fleet, and on the land-side against a possible attack by his land forces.[3]
New York in 1776.
The second measure looked to defending the city from an attack in the rear. At this time New York City occupied only a very small section of the southern part of the island which it has since outgrown. A few farms and country seats stretched up beyond Harlem, but the major part of the island was to the city below as the country to the town, retaining all its natural features of hill and dale unimpaired. At this time, too, the only exit from the island was by way of King's Bridge,[4] twelve miles above the city, where the great roads to Albany and New England turned off, the one to the north, the other to the east, making this passage fully as important in a military sense, as was the heavy drawbridge thrown across the moat of some ancient castle.
Fort Washington.
Fort Washington[5] was, therefore, built on a commanding height two and a half miles below King's Bridge, with outworks covering the approaches to the bridge, either by the country roads coming in from the north or from Harlem River at the east. These works were never finished, but even if they had been they could not solve the problem of a successful defence, because it lay always in the power of the strongest army to cut off all communication with the country beyond—and that means the passing in of reënforcements or supplies—by merely throwing itself across the roads just referred to. This done, the army in New York must either be shut up in the island, or come out and fight, provided the enemy had not already put it out of their power to do so by promptly seizing King's Bridge. And in that case there was no escape except by water, under fire of the enemy's ships of war.
One watchful eye, therefore, had to be kept constantly to the front, and another to the rear, between positions lying twelve to thirteen miles apart, and separated by a wide and deep river.
It thus appears that the defence of New York was a much more formidable task than had, at first, been supposed, and that an army of 40,000 men was none too large for the purpose, especially as it was wholly impracticable to reënforce King's Bridge from Brooklyn, or vice versa. But from one or another cause the army had fallen below 25,000 effectives by midsummer, counting also the militia, who formed a floating and most uncertain constituent of it. For the present, therefore, King's Bridge was held as an outpost, or until the enemy's plan of attack should be clearly developed; for whether Howe would first assail the works at Brooklyn, Bunker Hill fashion, or land his troops beyond King's Bridge, bringing them around by way of Long Island Sound, were questions most anxiously debated in the American camp.
However, the belief in a successful defence was much encouraged by the recent crushing defeat that the British fleet had met with in attempting to pass the American batteries at Charleston. Thrice welcome after the disasters of the unlucky Canada campaign, this success tended greatly to stiffen the backbone of the army, in the face of the steady and ominous accumulation of the British land and naval forces in the lower bay. Then again, the Declaration of Independence, read to every brigade in the army (July 9), was received with much enthusiasm. Now, for the first time since hostilities began, officers and men knew exactly what they were fighting for. There was at least an end to suspense, a term to all talk of compromise, and that was much.