After the Battle of Bunker Hill, neither the British nor the colonists could claim easy victory.

The British had captured the ground they sought, but at enormous cost. Colonial forces had been forced to retreat, yet they emerged from the battle with growing confidence that they could stand against Britain's professional army. The fighting convinced both sides that the conflict would likely become longer, bloodier, and more difficult than many had originally imagined.

Meanwhile, Boston remained the center of the war.

British troops controlled the city itself, but colonial militia forces surrounded it from the countryside, effectively placing the British under siege. Roads leading out of Boston were closely watched, and the Royal Navy remained Britain's primary link for supplying troops inside the city.

When George Washington arrived near Boston in July 1775 to assume command of the Continental Army, he found a military situation filled with challenges.

The colonial army surrounding the city lacked organization, discipline, and proper supplies. Soldiers came from multiple colonies and often operated according to local customs rather than unified military procedures. Weapons, ammunition, tents, uniforms, and food remained in short supply.

Disease also posed a serious threat.

Crowded camps, poor sanitation, limited medical knowledge, and inconsistent supplies created dangerous conditions for soldiers on both sides. Illness spread rapidly through military camps throughout the Revolution, often killing more men than combat itself.

Washington immediately began imposing greater order on the army.

He worked to improve discipline, strengthen defensive positions, organize supply systems, and transform the collection of colonial militias into a more professional fighting force. The task proved difficult and often frustrating. Enlistments were short, desertions occurred regularly, and Congress struggled to provide adequate funding.

At the same time, British commanders inside Boston faced growing problems of their own.

Maintaining thousands of troops inside a crowded city required constant supplies of food, fuel, and military equipment. British soldiers also remained vulnerable if colonial artillery could be placed on the high ground surrounding Boston Harbor.

Throughout the fall and winter of 1775, the siege settled into a tense stalemate.

Small skirmishes and artillery exchanges occurred periodically, but neither side launched a major offensive. Both armies spent much of the time strengthening defenses, gathering supplies, and preparing for future operations.

Washington understood that forcing the British out of Boston would require artillery powerful enough to threaten the city and harbor.

That opportunity arrived through an extraordinary effort led by a young bookseller and militia officer named Henry Knox.

Following the American capture of Fort Ticonderoga in upstate New York, Knox organized the transport of heavy cannons from the fort to Boston during the winter of 1775–1776. The mission required moving massive artillery pieces hundreds of miles across frozen rivers, rough roads, forests, and snow-covered terrain.

Against enormous odds, Knox succeeded.

In early 1776, the cannons finally arrived outside Boston.

Washington then made a bold strategic move.

During the night of March 4, 1776, American forces quietly fortified Dorchester Heights, high ground overlooking both Boston and the harbor. By morning, British commanders discovered colonial artillery positioned where it could threaten British ships and military positions throughout the city.

General William Howe immediately recognized the danger.

The British considered launching an assault similar to the attack at Bunker Hill, but weather conditions and the strength of the American defenses complicated the plan. Howe also understood that another costly frontal attack might produce devastating casualties.

Instead, British leaders chose withdrawal.

On March 17, 1776, British forces evacuated Boston by sea, taking thousands of soldiers and many Loyalist civilians with them to Halifax, Nova Scotia.

The evacuation marked the first major American victory of the Revolutionary War.

Colonial forces had successfully driven the British army from one of America's largest cities. The victory greatly boosted Patriot morale and strengthened confidence in Washington's leadership.

Yet Washington also recognized an important reality.

The British had not been defeated permanently. Their army remained powerful, well-trained, and capable of launching future operations elsewhere along the American coast.

The war was only beginning.