British troops had been under siege in Boston when the American Revolutionary War broke out in April 1775.

They had defeated Patriot forces in the Battle of Bunker Hill, suffering very high casualties.

When news of this expensive British victory reached London, General William Howe and Lord George Germain, the British official responsible, had determined that a "decisive action" should be taken against New York City using forces recruited from throughout the British Empire as well as troops hired from small German states.

General George Washington, recently named by the Second Continental Congress as the commander-in-chief of the Continental Army, echoes the sentiments of others that New York is "a post of infinite importance", and begins the task of organizing military companies in the New York area when he stops there on his way to take command of the siege of Boston.

In January 1776 Washington orders Charles Lee to raise troops and take command of New York's defenses.