The Siege of Boston (19 April 1775-17 March 1776) was a major action and the opening phase of the American Revolutionary War. Almost 20,000 New England militiamen surrounded the city of Boston, Massachusetts, which was occupied by 11,000 British troops under the generals Thomas Gage, William Howe, and Henry Clinton. The city was evacuated in March 1776 after the colonists fortified Dorchester Heights with artillery.
Following the Battles of Lexington and Concord, militia from surrounding Massachusetts communities blocked land access to Boston. The Continental Congress formed the Continental Army from the militia, with George Washington as its commander-in-chief. In June 1775, the British suffered heavy losses at the Battle of Bunker Hill, during which the British drove the Continentals from their siege positions on Bunker and Breed's Hills. For the rest of the siege, military actions were limited to occasional raids, minor skirmishes, and sniper fire.
In November 1775, Washington sent the 25-year-old former bookseller Henry Knox to Fort Ticonderoga to gather its captured artillery for the Siege of Boston. Knox's "Noble train of artillery", some 60 tons of cannons and other armaments, was brought along poor-quality roads and frozen rivers in the snow. These cannons arrived in January 1776, and Washington had Dorchester Heights fortified in March 1776. William Howe, seeing his positions in Boston as indefensible, reached a gentleman's agreement with Washington; if Washington allowed for Howe to evacuate the garrison of the city and its loyalist inhabitants without being fired upon, Howe would not burn the city. 120 British ships evacuated 10,000 British troops and 1,000 loyalists to Halifax, Nova Scotia, and the loyalists and British soldiers ravaged Boston before leaving. Washington's bluff had won America a strategic victory, with Boston becoming an American stronghold.
Background[]
Two decades of turbulent unrest in New England's leading seaport had shut down its commerce, radicalized many of its citizens, and brought war to its doorstep. The 1770 Boston massacre and Boston Tea Party in 1773 inflamed tensions in the Massachusetts capital. Its subsequent occuptaion by British soldiers fanned the fires to an inferno. After the battles of Lexington and Concord, British troops were besieged in the town of Boston by a ring of rebellious militia units, soon led by a newly appointed and untried commander in chief: George Washington.
History[]
As the new year dawned on snowbound Boston, it revealed a city choked off by six months of siege, encircled by 14 miles of entrenchments. To any British sentry, the rebel militiamen manning those trenches looked no different from usual, but the change in the Patriots' flag indicated that at least one thing was new. On 1 January 1776, Washington raised a banner with 13 alternating red-and-white stripes, and a Union Jack in the corner, over Cambridge's Prospect Hill. The 13-gun salute honoring the Congress flag proved that his army, although low on supplies, was not entirely out of powder.
Washington desperately needed weapons and reinforcements. He had practically disbanded one army - its enlistments having expired - and raised another to take its place. With few muskets at his men's disposal, many were armed with only spears or pikes. This was about to change, though, with the arrival of siege guns brought by Henry Knox. On 18 January, Knox rode into Framingham, a few miles from the army's Cambridge headquarters, with 52 cannons and mortars sledged nearly 300 miles from Fort Ticonderoga, a recent Patriot gain. On this journey, Knox had crossed two lakes, one river, and rugged mountain ranges, with the ordnance drawn by slow-plodding oxen. Washington's prayers had been answered.
Cabin fever[]
Holed up in Boston, General William Howe was more than ready to leave the city. He had been ordered to evacuate months ago, but Atlantic storms had scattered the promised transports. Winter gales had then set in, confining him to Government House. At least he had a good supply of firewood. Fuel had become so scarce in the beiseged city that wooden fences, dilapidated houses, and frame churches had to be pulled down and used for the fire. Even the elms on Boston Common were felled. There were also food shortages, resulting in a thriving black market, but the British officers still managed to put on plays, balls, and other diversions. Howe's dragoons took over the venerable Old South Meeting House, ripped out the pulpit and pews, spread tanbark over the floors, and established a riding school. Meanwhile, in the lines and outer works, his troops shivered through the snowstorms, grew bored, and misbehaved. The number of floggings rose.
Intimidation tactics[]
With Knox's artillery now in his possession, Washington decided to seize Dorchester Heights, a hilltop looming over the city from the southetast. Neither army had fortified the treeless slopes because of the exposure to enemy fire this would have entailed. Washington, though, had no intention of digging earthworks in that frozen ground. On 2 March, using some of the cannons brought by Knox, the rebels began a two-day bombardment of Boston. Then, on the night of 4 March, while the cannonading continued, 3,000 men and 300 ox carts carried fascinees - bundles of brushwood fitten in wooden frames - bales of hay, and barrels filled with dirt and rocks to the summit of Dorchester Heights. Nearby orchards had been chopped down to create an abatis (a wall of felled trees) to protect the improvised works. By dawn the next day, about 20 pieces of artillery, including 24-pounders and mortars from Ticonderoga, had been heaved into place.
Howe was stunned at what he saw through his spyglass the next morning. The rebels had done more in one night, he muttered, than his army could in a month. The works on Dorchester Heights appeared to be bristling with cannons. Even if the British commander had known that Washington did not have enough powder or shot to prolong the bombardment, the guns could not be ignored. Howe had to attack. That rainy afternoon - as the Royal Navy began moving its warships out of range of the Patriots' cannons - Howe's force embarked on teh remaining transports and anchored them under the Heights, ready for the offensive. Soon, however, the rain turned into a gale, blowing the transports into each other and fouling their anchors. Howe's attack was called off, while the Americans strengthened their lines.
Bitter retreat[]
Evacuation was Howe's only option. On 17 March, scarlet-coated columns filed out of Charlestown or marched off the Common, tramping down to the wharves. Washington's lines remained quiet: Howe had threatened to torch the town if rebels fired a shot. Nearly 9,000 men, and as many horses and stores as possible, were rowed out to the waiting ships. So were 1,000 Loyalists, stunned that a rebel horde had forced the British Army to quit the city. Howe's men left behind nearly 100 pieces of ordnance. Heavier guns were spikde but many others were serviceable. They also left pillaged houses, broken furniture, and "crows-feet" - razor sharp four-pointed metal spikes - scattered over the streets. The Royal Navy fleet tarried off Boston for another 10 days, its sails disappearing from view on 27 March. The ships steered north to the British base at Halifax, Nova Scotia. Washington, the new commander in chief, had won his first victory.
Aftermath[]
When Howe's fleet sailed out of Boston Harbor, it spelled the end of revolutionary conflict in the place where it all began. Awaiting reinforcements - more than 16,500 troops, including 12,200 Hessians - General Howe turned his attention from Boston to New York. Anticipating the British attack, Washington ordered his army to Manhattan. Post-evacuation, Boston ceased to be a military theater and remained in Patriot hands. Its port was key to Patriot shipbuilding and repairs.