The British plan to cut off New England from the other colonies (1776–1777) had three prongs:
The Royal Navy's superiority allowed a tight blockade from Maine to Connecticut, choking off maritime trade, fishing, and supply ships. This caused shortages of salt, cloth, medicine, and munitions.
General Burgoyne led ~8,000 troops south from Quebec via Lake Champlain/Hudson River corridor to Albany, aiming to link with Howe's forces from New York City—physically severing New England.
British raids up the Hudson Valley and into New Jersey/Connecticut coast disrupted overland supply routes and destroyed stores (e.g., Danbury, 1777).
Saratoga convinced France to enter the war openly (1778), turning a colonial rebellion into a global conflict. The isolation plan backfired—it united the colonies further and brought powerful allies.