Boston's liberation was a bluff that worked

McCullough opens with the Continental Army's siege of British-occupied Boston in early 1776, a standoff that Washington finally broke by secretly fortifying Dorchester Heights overlooking the city with cannons hauled overland from Fort Ticonderoga — an operation organized by Henry Knox that moved dozens of heavy guns across roughly three hundred miles of frozen terrain in winter. Once the guns were in place overnight, British commander General William Howe faced the choice of a costly assault or withdrawal.

Howe chose to evacuate, and British forces along with thousands of Loyalist civilians departed Boston by ship in March 1776, handing the Americans their first major strategic success of the war without a decisive battle actually being fought. McCullough emphasizes how much of this triumph rested on logistics and audacity rather than combat: Knox's near-impossible artillery transport, and Washington's willingness to gamble on a fortification effort the British could have crushed if they'd moved faster.

The victory gave the fledgling army — and the American cause more broadly — a badly needed jolt of legitimacy and confidence heading into a much harder year.

Takeaway: sometimes the most decisive battle is the one your opponent decides not to fight.