From April 1775 to March 1776, in the opening stage of the American Revolutionary War (1775-83), colonial militiamen, who later became part of the Continental army, successfully laid siege to British-held Boston, Massachusetts. The siege included the June 1775 Battle of Bunker Hill, in which the British defeated an inexperienced colonial force that nevertheless managed to inflict heavy casualties. In July 1775, General George Washington arrived in the Boston area to take charge of the newly established Continental army. In early March 1776, Washington’s men fortified Dorchester Heights, an elevated position just outside of Boston. Realizing Boston was indefensible to the American positions, the British evacuated the town on March 17 and the siege came to an end.

Siege of Boston: Background

For more than a decade before the outbreak of the Revolutionary War, tensions had been building between American colonists and the British authorities. Attempts by the British government to raise revenue by taxing the colonies met with heated protest among many colonists, who resented their lack of representation in Parliament and demanded the same rights as other British subjects. Colonial resistance led to violence in 1770, when British soldiers opened fire on a mob of colonists, killing five men in what was known as the Boston Massacre.

Did you know? Since 1901, Bostonians have celebrated the end of the Siege of Boston with an official holiday known as Evacuation Day, observed every March 17th.

After December 1773, when a band of Bostonians dressed as Indians boarded British ships and dumped hundreds of chests of tea into Boston Harbor, an outraged Parliament passed a series of measures designed to reassert imperial authority in Massachusetts. In response, a group of colonial delegates (including George Washington of Virginia, John and Samuel Adams of Massachusetts, Patrick Henry of Virginia and John Jay of New York) met in Philadelphia in September 1774 to give voice to their grievances against the British crown.

This First Continental Congress did not go so far as to demand independence from Britain, but it denounced taxation without representation, as well as the maintenance of the British army in the colonies without their consent, and issued a declaration of the rights due every citizen, including life, liberty, property, assembly and trial by jury. The Continental Congress voted to meet again in May 1775 to consider further action, but by that time violence had already broken out. On April 19, local militiamen clashed with British soldiers in Lexington and Concord, Massachusetts, marking the first shots fired in the Revolutionary War.

Siege of Boston and Battle of Bunker Hill

Following the battles of Lexington and Concord, colonial militiamen surrounded Boston in an effort to contain the British troops there. However, because the British maintained control of Boston Harbor, they were able to receive additional soldiers and supplies.

On June 16, 1775, having learned that the British were planning to send troops from Boston to occupy the hills surrounding the town (Boston was incorporated as a city in 1822), colonial militiamen under Colonel William Prescott (1726-95) built fortifications on top of Breed’s Hill, overlooking Boston and located on the Charlestown Peninsula. (The men originally had been ordered to construct their fortifications atop Bunker Hill but instead chose the smaller Breed’s Hill, closer to Boston.) The next day, British troops under Major General William Howe (1729-1814) and Brigadier General Robert Pigot (1720-96) attacked the Americans at Breed’s Hill. The British went on to win the so-called Battle of Bunker Hill, and Breed’s Hill and the Charlestown Peninsula fell firmly under their control. Despite their loss, the inexperienced and outnumbered colonial forces inflicted significant casualties against the enemy, and the battle provided the Patriots with an important confidence boost.

After the Battle of Bunker Hill, the Siege of Boston turned into a stalemate for a number of months.

Siege of Boston and Fortification of Dorchester Heights

In early July 1775, General George Washington (1732-99) arrived in the Boston area to take command of the newly established Continental army. Washington’s goal was to drive the British from Boston, and in order to do this, his army required weapons. That winter, Colonel Henry Knox (1750-1806) oversaw an expedition to transport more than 60 tons of captured military supplies from New York’s Fort Ticonderoga back to Boston. In May 1775, the British-held Ticonderoga and nearby Fort Crown Point had been seized by colonial forces under Benedict Arnold (1741-1801) and Ethan Allen (1738-89). After a challenging journey across snowy terrain, the armaments, including more than 50 cannon, reached the Boston area in late January 1776.

Some of the cannon were placed in fortifications around Boston, and beginning on March 2 used to bombard the British for two days straight. On the night of March 4, several thousand of Washington’s men and more of the Ticonderoga cannon were moved into position at Dorchester Heights, overlooking Boston and its harbor. British General William Howe (1729-1814) realized his troops could not defend the town against the Continental army’s elevated position at Dorchester Heights, and soon decided to leave. On March 17, the eight-year British occupation of Boston ended when British troops evacuated the town and sailed to the safety of Nova Scotia, a British colony in Canada.

Siege of Boston: Aftermath

After the Siege of Boston, the Revolutionary War continued for seven more years. The Battle of Yorktown, which ended in October 1781 with the surrender of British forces under Lieutenant General Charles Cornwallis (1738-1805) to a combined American and French force, was the last major land battle of the war. However, the Revolutionary War did not officially end until the September 1783 signing of the Treaty of Paris, in which Britain recognized the independence of the United States.

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