General Howe believed that a single overwhelming victory could bring a swift end to the rebellion. Merely capturing territory or cities, he argued, would prove fruitless as long as the patriot army remained intact. By targeting the vital commercial hub of New York City, however, Howe hoped to draw the Continental Army into a decisive battle that would shatter Washington’s army and lead to a peace treaty on British terms.
"I shall not fail to make the most of the time that remains, by a vigorous exertion of the force I have the honor to command, in the hope of bringing this unnatural rebellion to a speedy conclusion. I am of the opinion that peace will not be restored in America until the rebel army is defeated, should the enemy offer battle in the open field we must not decline it"
General William Howe, Dispatch No. 17, sent on 7 June 1776General Howe’s letters to Lord Germain (no.17-19), referring to his frustration at being kept at Halifax before departing for Sandy Hook, and reporting upon regiments sent to distress rebels at New York : (2017). Adam Matthew Digital. http://www.colonialamerica.amdigital.co.uk/Documents/Details/CO_5_93_Part_2_010