Positioned at the southern end of Manhattan Island where the ocean waters of the Atlantic mingled with the fresh water flowing south from Canada, New York City The system of waterways that connected New York City to Canada, a network that ran from the Hudson River to Lake George and then to Lake Champlain, provided the most efficient invasion route between the American colonies and the British strongholds to the north. A member of the Second Continental Congress, Massachusetts delegate John Adams, observed that whomever controlled New York City and its extensive port and warehouse facilities enjoyed a strategic advantage in the war.
"That it is expedient, and even necessary to be done, by Some Authority or other, I believe will not be doubted by any Friend of the American Cause, who considers the vast Importance of that City, Province, and the North River which is in it, in the Progress of this War, as it is the Nexus of the Northern and Southern Colonies, as a Kind of Key to the whole Continent, as it is a Passage to Canada to the Great Lakes and to all the Indians Nations. No Effort to secure it ought to be omitted."
John Adams' letter to George Washington on 6 January 1776.www.founders.archives.gov