Historians have always differed as to the loss of the Americans in the battle of Brooklyn. Colonel Trumbull was commissary-general during the engagement, and was employed, when the retreat was determined upon, in procuring vessels in which to remove the army. By virtue of his position he possessed peculiar facilities for knowing the true state of affairs. Two days after the retreat he wrote the following letter to his father, giving an account of Washington's masterly effort:
New York, September 1, 1776.
Honored Sir,—We have been obliged to retreat from Long Island and Governor's Island, from both of which we got off without loss of men. We left a great part of our heavy artillery behind. The field train is off. We are in hourly expectation that the town will be bombarded and cannonaded, and the enemy are drawing their men to the eastward of Long Island, as if they intended to throw a strong party over on this island, near Hell Gate, so as to get on the back of the city. We are preparing to meet them. Matters appear to be drawing near a decisive engagement. General Sullivan is allowed to come on shore, upon his parole, and go to Congress, on the subject of exchange of himself, Lord Stirling, and a large number who are prisoners; by the best accounts we yet have, we have lost in last week's defeat about 800 men killed and missing; how many of each is not yet known. I rather expect that they will push in a body of troops between the town and our party at and near Kingsbridge. If they do, we shall have them between two fires, and must push them to the last extremity, or be killed or taken prisoners. The result is in the hands of the Almighty Disposer of all events.
I am, honored sir, your dutiful son,
Joseph Trumbull.
While the battle was raging with so much fury, Washington was in New York, watching the movements of the British fleet. He was filled with anxiety and alarm, as he considered that an important crisis had arrived. Becoming satisfied during the day that there was no intention on the part of the fleet to attack the city, he passed over to Brooklyn and took his station at Fort Putnam.
Here he witnessed the terrible rout and slaughter which befell Sullivan, with no means at his command to send succor or assistance. He also beheld the heroic conduct of the men under Stirling, and was convinced that resistance on their part was in vain. As Washington noticed the bravery of the Maryland troops in the bayonet charge, he exclaimed, "Good God, what brave fellows I must this day lose."
Thus terminated the battle on the 27th. The slaughter had been terrible on both sides. The flower of the American army was destroyed, and many valuable and efficient officers were taken prisoners. General Howe felt jubilant over his success, and made preparations to advance upon the American lines. Within those lines were 3000 brave men who were encouraged by the presence of Washington. Had an attempt been made to take their fortifications, they would not have been yielded without the destruction of hosts of the invaders. As Howe did not know the strength of the Americans, he deemed it prudent not to make the attempt, and encamped for the night. It was not singular, under the circumstances, that Washington should feel alarmed. He was satisfied that resistance would be useless, and that something must be done to save the remnant of his army.
The Hessians, who had been hired by the British Government, were trained soldiers. Of the men so procured the Landgrave of Hesse Cassel furnished 12,000 infantry, the Duke of Brunswick 3900, and the Count of Hanau 360. War was their profession, and in its destructive work they seemed to take great delight. In the engagements on Long Island they took an active part, and manifested their disposition by showing no quarter. The sight of blood served to madden them, and led them on to renewed acts of diabolism and ferocity. Nothing satisfied their rapacity. After the retreat of the Americans from Long Island, and its occupation by the British, many of these Hessians took possession of and were quartered in the large old-fashioned Dutch houses, and made themselves free with everything on which they could lay their hands.
The morning of the 28th of August arrived. A thick mist enshrouded the earth with gloom. Washington did not manifest any despondency, and as he inspected the works and defenses had a cheerful word of encouragement for the men. Early in the morning several regiments of Massachusetts soldiers crossed to the island, and were received with manifestations of joy by the weary toilers of the day and night past. With this addition the force of the Americans numbered 9000 men. The battle was now renewed by the British, who commenced a heavy cannonade on the American works. Providence seemed to smile upon the American cause. The clouds poured forth rain in torrents, which, while it produced much physical discomfort to the patriots, who were compelled to stand knee deep in water, served also to restrain and prevent the enemy from engaging in the conflict.
Washington realized the necessity of immediate action. A council of officers was summoned, and by his advice the conclusion was reached to evacuate the island. The council convened by Washington to deliberate upon this important subject was composed of the commander-in-chief, General Washington; major generals Putnam and Spencer, brigadier generals Mifflin, McDougall, Parsons, Scott, Wadsworth, and Fellows. In Stiles's account of the battle of Long Island, he says that "the old Cornell House, afterwards known as the Pierrepont Mansion, which formerly stood on the line of the present Montague Street, near the little iron footbridge which spans the carriageway, was the headquarters of Washington during this important contest. It was a spacious and costly house having large chimneys, from which it was known as the 'Four Chimneys;' and upon its roof a telegraph was arranged by which communication was held with New York."
Stiles maintains that both Lossing and Onderdonk erred in stating that the council met in the Dutch church on Fulton Street, but that they met in this old house. In supporting his opinion he quotes the authority of Colonel Fish, the father of Governor Hamilton Fish, and one of Washington's military family, who in 1824, during Lafayette's visit to Brooklyn, called the attention of the distinguished visitor to the fact, and designated the very positions in the room occupied by the members of that council.
The business brought before the council was very important, and the execution of the scheme adopted required military skill and strategy to insure success. It would not have answered to retreat during the day, as their movements would have been noticed and checkmated by the enemy. It was resolved to effect the withdrawal of the troops that night. Every move required the utmost caution and secrecy. As boats were needed to transport the troops, and the collecting together of them might excite the suspicion of the British, it was reported that the Americans intended to attack the enemy in the rear, and to accomplish this end had determined to transport troops to the line of Queens County at Hell Gate. This plan was adopted to deceive the enemy. In pursuance of the resolution of the council, orders were issued to move every available boat to Brooklyn, and have them in readiness for embarkation at midnight. So cautious were the officers conducting this retreat that all orders were given in whispers, and communicated to the men in the same manner. The state of the weather favored the movements of Washington. During the day rain had fallen in copious showers. As the mantle of night covered the earth, a heavy fog appeared, which, with the drizzling mist, served to deceive the enemy, and render them less vigilant. In order to mislead the British officers and soldiers, Washington kept several companies marching to and from the ferry landing, while their associates were embarking. Washington himself superintended the embarkation of the troops, who began to move about ten o'clock. The darkness of the night aided materially in the accomplishment of the work. To add to the deception, fires were kept burning until the last moment. All the troops were safely embarked. The boatmen labored cheerfully during the night watches, and when at last the fog passed away, and they beheld the clear cerulean sky above them, they also rejoiced that a kind Providence had directed their boats to a safe harbor on the shores of the upper part of the city of New York.