Had the East River been occupied by the British fleet, it could, while cutting off half of our army from the defence of New York, at the same time have threatened the city front pending the transportation of the British army by water to points above the city from whence to turn either or both flanks of Manhattan Island. Washington, thus shut up, would have been compelled to fight at great disadvantage, and possibly surrender at discretion.
Even admitting that the battle of Long Island was necessary, Howe, in dividing his army into three masses, stretching over a line of more than ten miles, ran great risk of being beaten in detail had all of the American forces on the island been concentrated at a central position, ready to be thrown successively upon his isolated columns. It is true the undisciplined American forces might not have been able to cope in the open field with British and German regulars; but Howe had no right to presume their inferiority after his own experience of their good conduct at Bunker Hill and Clinton's trial at Sullivan's Island.
The American general also committed a great military blunder in leaving with raw troops the shelter of the Brooklyn intrenchments for the precarious protection of the Long Island Ridge, several important passes in which were left entirely unguarded, though Washington had ordered their careful observation.
After the retreat of the American army to New York, Howe wasted two precious weeks, during which Washington had time to organize his defence; and when the British general crossed the East River, he committed a great mistake in debarking at Kip's Bay,—a halfway measure which involved a long land march to his objective, White Plains. Washington, with great vigor, seized his advantage, and, by availing himself of his shorter interior line, arrived first at the coveted position and fortified it. Had Howe moved to this point by water immediately after the battle of Long Island, he undoubtedly would have succeeded in turning Washington's left flank, and would thus have cut off his retreat. The British general's delay of two months after the battle of Long Island in moving less than thirty miles to reach White Plains was inexcusable. In a shorter period Moltke began and ended the campaign of 1866, which so humbled the great power of the Austrian empire.
When Howe decided to attack the American army at White Plains he should have thrown his entire force upon Washington's centre, and thus have won a decisive victory with his superior troops; whereas he used less than one third of his army in driving Washington's right wing from Chatterton's Hill upon his main body, which then successfully retreated before the tardy and inert British general.
Howe's good fortune in capturing Fort Washington was due more to the treason of Magaw's adjutant and to Washington's yielding to bad advice, than to any skill of the British commander.[724]
With the invasion of New Jersey by the Anglo-Hessian army all military operations at the mouth of the Hudson were terminated. The struggle for the control of this great river was to be transferred to its upper waters, and it was expected that the coming campaign would be so conducted as soon to force the whole power of the colonies into silence and submission.
General Gates, who was appointed the successor of Sullivan in the command of the army of Canada, was, says Horace Walpole, "the son of a housekeeper of the second Duke of Leeds." He had neither brilliant qualities nor military genius, but possessed the vanity and ambition to covet the highest position, for the attainment of which he resorted to disgraceful intrigue. When assigned to this command, in June, 1776, the army of Canada was flying to Crown Point; so, like Sancho Panza, Gates found himself a governor without a government; but, nothing abashed, he at once claimed the command of the Northern department, then under Schuyler. Congress sustained the latter, whereupon Gates took post at Ticonderoga, where the remnant of the American army had retired upon the abandonment of Crown Point, and promptly adopted vigorous measures to put the work in good condition for defence and to reinforce its garrison against any forward movement of General Carleton.
To secure control of Lake Champlain, a squadron of small vessels was ordered to be constructed at its head (Skenesborough), which, to the number of nine, mounting in all fifty-five guns, were completed by the middle of August. Arnold, in command of these and some additional galleys from Ticonderoga, moved down to the foot of the lake, and anchored his vessels across it to bar the passage of the enemy.