He was inclined to believe that Philadelphia would be the first and chief objective, and wished to hold himself in readiness for marching thither at a moment's warning; but again there were rumors of an invasion from Canada by way of the lakes and the Hudson, so this region must be protected.
Existing forts must be strengthened, others erected, a boom stretched across the Hudson to impede the passage of British ships, and obstacles of all kinds placed in the path of the British, should they advance northward.

Needing a reliable man in this emergency, Washington sent Putnam to Peekskill, on the Hudson, preceded by a letter to General McDougall, then in command there, which was, to say the least, not very flattering to the gallant soldier who had been his right-hand man in the various retreats through the Jerseys.

"You are acquainted with the old gentleman's temper," he wrote; "he is active, disinterested, and open to conviction," etc.
Washington would have been more fortunate if all his officers had been as "active, disinterested, and open to conviction" as Old Put--for instance, Lee, Arnold, Gates, and others--but he had allowed his prejudices to warp his former opinion of Putnam's sterling qualities.
Hardly had Putnam begun his work on the Hudson before there was a mighty movement in the port of New York, and, fearing there might be an attempt upon Philadelphia, Washington drew upon the old soldier's command until he had scarcely a thousand men at call.

Then followed the commander's magnificent strategy at Middlebrook, whereby he finally defeated the British plans and brought about the complete evacuation of New Jersey, after which Putnam was strengthened in his position; only to be weakened again, the process being repeated until he felt called upon to protest.
Putnam was later accused by Hamilton, Washington's aide-de-camp, of making a "hobby-horse" out of his desire to march upon New York, and of riding it on all occasions; but it was no less a hobby-horse with him than the defense of Philadelphia was with his Commander-in-Chief, who many times imperiled the safety of other sections by withdrawing troops in hot haste and flying to the succor of a city which was captured and occupied by the British notwithstanding.
Washington rode his hobby-horse full-tilt at the unfortunate Putnam and threw him to the ground.

With one hand, as it were, he wrote him to keep an eye on the movements of the enemy and be fully prepared to meet them; but with the other he signed an order for the weakening of his force.
The consequences came when Burgoyne, having descended from Canada and invaded northern New York, Putnam found himself between two fires, that of the former and that of Sir Henry Clinton, who finally set out on the long-meditated trip up the Hudson in order to cooperate with the southward-marching army.
Putnam had learned of the successive moves on the military chess-board as Burgoyne progressed in his triumphal march.