[130] The British forces, including more than a hundred ships and thousands of troops, began arriving on Staten Island on July 2 to lay siege to the city.[131] After the Declaration of Independence was adopted on July 4, Washington informed his troops in his general orders of July 9 that Congress had declared the united colonies to be "free and independent states".[132]
Howe's troop strength totaled 32,000 regulars and Hessian auxiliaries, and Washington's consisted of 23,000, mostly raw recruits and militia.[133] In August, Howe landed 20,000 troops at Gravesend, Brooklyn, and approached Washington's fortifications, as George III proclaimed the rebellious American colonists to be traitors.[134] Washington, opposing his generals, chose to fight, based upon inaccurate information that Howe's army had only 8,000-plus troops.[135] In the Battle of Long Island, Howe assaulted Washington's flank and inflicted 1,500 Patriot casualties, the British suffering 400.[136] Washington retreated, instructing General William Heath to acquisition river craft in the area. On August 30, General William Alexander held off the British and gave cover while the army crossed the East River under darkness to Manhattan Island without loss of life or materiel, although Alexander was captured.