Siege of Boston Begins

After the battles at Lexington and Concord, thousands of New England militiamen surrounded Boston, trapping British forces on the peninsula. What began as a spontaneous reaction became an organized siege that would last eleven months.

The besieging forces lacked central command at first—men from different colonies operated independently. General Artemas Ward of Massachusetts provided some coordination, but the siege gained coherence only when George Washington arrived in July 1775 to take command of what became the Continental Army.

The British held advantages: naval support, professional training, interior fortifications. But they could not break out without unacceptable casualties, and supply ships had to run the risk of colonial interference. Boston became a trap for both sides—until cannon changed the equation.