Always deliberate in his planning, Howe did not begin operations until June. He maneuvered for a time in New Jersey, keeping even his own subordinates guessing about his intentions. He may have been watching to see if Washington would lead his army north to intercept Burgoyne. He may have been waiting for his brother to ready the fleet. Finally, he marched his troops back to New York City and completely evacuated New Jersey.

Some of Howe's officers objected to his plan to sail to Philadelphia. Colonel Charles Stuart wrote to Burgoyne that it made him “tremble for the con-sequences.” Henry Clinton argued that Howe should approach Philadelphia overland, across New Jersey. Clinton was not convinced that Philadelphia was a worthwhile objective, and marching by land would keep Howe within range of supporting both New York City and Burgoyne's advance. Howe responded by stripping more units from Clinton's garrison in New York City, leaving him capable of only a “d – d starved deffencive.”

Howe loaded his men aboard ship in July. There the troops stayed for two hot and humid weeks while Howe lingered in port. He finally set sail on July 23. His fleet of 260 ships carried 15,000 soldiers and their equipage. On July 29, the fleet arrived off Delaware Bay. Sailing up the Delaware River would soon have put Howe within striking distance of Philadelphia. A report that the Americans were constructing defenses along the river persuaded Howe to make for the Chesapeake instead, but the fleet was beset by contrary winds and frustrating calms.

Howe was not able to disembark his army at Head of Elk until August 25. He had lost a month at sea. By the time Howe made land, Burgoyne's situation was growing critical; at Chesapeake Bay there was nothing Howe could do for him. His own army was weakened by the weeks spent confined below decks in the sweltering heat. Many horses had died and many men were sick from bad air, bad food, and bad water.

Washington's army had spent a hard winter at Morristown, New Jersey. It continued to suffer from a lack of such necessities as clothing and medicine. Smallpox spread through the army until Washington arrested its progress with a rigorous program of enforced inoculations. The food situation was so serious that Washington used the special powers granted him by Congress to commandeer food from the civilian population. The size of the army dipped dangerously over the winter. Then Washington began to benefit from the new recruitment plan for the Continental army, which offered men a bounty of twenty dollars and the promise of 100 acres of land if they enlisted for three years or the duration of the war. Around 1,000 of Washington's veterans re-enlisted for this inducement. By May, 8,000 recruits had joined his army.

Howe's movements that summer mystified Washington. Aware that Burgoyne was on his way, Washington expected Howe to attack up the Hudson. When Howe sailed away, Washington was uncertain about his destination. The appearance of the fleet off the Delaware convinced Washington that Howe was going to land and make straight for Philadelphia. When the fleet sailed away, he thought for a time that it might be a feint designed to misdirect his army, and he prepared to order part of his army back to New York. The root of Washington's problem in deducing Howe's plans lay in the fact that he could not understand “why he should go to the southward rather than cooperate with Mr. Burgoyne.” Not until the British fleet appeared in Chesapeake Bay was Washington convinced that Philadelphia was Howe's objective.