Fortification of Dorchester Heights
Encyclopedia
The Fortification of Dorchester Heights was a decisive action early in the American Revolutionary War
that precipitated the end of the siege of Boston
and the withdrawal of British troops from that city.
On March 4, 1776, troops from the Continental Army
under George Washington
's command occupied Dorchester Heights
, a series of low hills with a commanding view of Boston
and its harbor
, and mounted powerful cannon
s there. General William Howe
, commander of the British forces occupying the city, considered contesting this act, as the cannon threatened the town and the military ships in the harbor. After a snowstorm prevented execution of his plans, Howe decided instead to withdraw from the city. The British forces, accompanied by Loyalist
s who had fled to the city during the siege, left the city
on March 17 and sailed to Halifax, Nova Scotia.
began on April 19, 1775, when, in the aftermath of the Battles of Lexington and Concord
, Colonial militia surrounded the city of Boston. Benedict Arnold
, who arrived with Connecticut militia to support the siege, told the Massachusetts Committee of Safety
that cannons and other valuable military stores were stored at the lightly defended Fort Ticonderoga
, and proposed its capture. On May 3, the Committee gave Arnold a colonel
's commission and authorized him to raise troops and lead a mission to capture the fort. Arnold, in conjunction with Ethan Allen
, his Green Mountain Boys
, and militia forces from Connecticut and western Massachusetts, captured the fort
and all of its armaments on May 10.
After George Washington
took command of the army outside Boston in July 1775, the idea of bringing the cannons from Ticonderoga to the siege was raised by Colonel Henry Knox
. Knox was eventually given the assignment to transport weapons from Ticonderoga to Cambridge. Knox went to Ticonderoga in November 1775, and, over the course of 3 winter months, moved 60 tons of cannons and other armaments by boat, horse and ox-drawn sledges, and manpower, along poor-quality roads, across two semi-frozen rivers, and through the forests and swamps of the lightly inhabited Berkshires
to the Boston area. Historian Victor Brooks has called Knox's feat "one of the most stupendous feats of logistics" of the entire war.
, had long been aware of the importance of the Dorchester Heights
, which, along with the heights of Charlestown
, had commanding views of Boston and its outer harbor. The harbor was vital to the British, as the Royal Navy
, at first under Admiral Samuel Graves
, and later under Admiral Molyneux Shuldham
, provided protection for the troops in Boston, as well as transportation of supplies to the besieged city. Early in the siege, the British planned to seize both of these heights, beginning with those in Dorchester, which had a better view of the harbor than the Charlestown hills. It was the leaking of this plan that precipitated events leading to the Battle of Bunker Hill
.
When Washington took command of the siege in July 1775, he considered taking the unoccupied Dorchester Heights, but rejected the idea, feeling the army was not ready to deal with the likely British attack on the position. The subject of an attempt on the heights was again discussed in early February 1776, but the local Council of Safety believed the British troop strength too high, and important military supplies like gunpowder too low, to warrant action at that time. By the end of February, Knox had arrived with the cannon from Ticonderoga, as had additional supplies of powder and shells. Washington decided the time was right to act.
and Cobble Hill in Cambridge
, and on Lamb's Dam in Roxbury. As a diversion against the planned move on the Dorchester Heights, he ordered these batteries to open fire on the town on the night of March 2, which fire the British returned, without significant casualties on either side. These cannonades were repeated on the night of March 3, while preparations for the taking of the heights continued.
On the night of March 4, 1776, the batteries opened fire again, but this time the fire was accompanied by action. General John Thomas
and about 2,000 troops quietly marched to the top of Dorchester Heights, hauling entrenching tools and cannon placements. Hay bales were placed between the path taken by the troops and the harbor in order to muffle the sounds of the activity. Throughout the night, these troops and their relief labored at hauling cannon and building earthworks overlooking the town and the harbor. General Washington was present to provide moral support and encouragement, reminding them that March 5 was the sixth anniversary of the Boston Massacre
. By 4 am, they had constructed fortifications that were proof against small arms and grapeshot
. Work continued on the positions, with troops cutting down trees and constructing abbatis
to impede any British assault on the works. The outside of the works also included rock-filled barrels that, while appearing to be a part of the defensive structure, could be rolled down the hill at attacking troops.
Washington anticipated that General Howe and his troops would either flee or try to take the hill, an action that would have probably been reminiscent of the Battle of Bunker Hill
, which was a disaster for the British. If Howe decided to launch an attack on the heights, Washington planned to launch an attack against the city from Cambridge. As part of the preparations, he readied two floating batteries and boats sufficient to carry almost 3,000 troops. Washington's judgment of Howe's options was accurate; they were exactly the options Howe considered.
, commander of the British fleet, declared that the fleet was in danger unless the position on the heights was taken. Howe and his staff then determined to contest the occupation of the heights, and made plans for an assault, preparing to send 2,400 men under cover of darkness to attack the position. Washington, notified of British movements, increased the forces on the heights until there were nearly 6,000 men on the Dorchester lines. However, a snow storm began late on March 5 and halted any chance of a battle for several days. By the time the storm subsided, Howe reconsidered launching an attack, reasoning that preserving the army for battle elsewhere was of higher value than attempting to hold Boston.
Howe, through intermediaries, informed Washington that the city would not be burned to the ground if his troops were allowed to leave unmolested. After several days of activity, and several more of bad weather, the British forces departed Boston by sea on March 17 and sailed to Halifax, Nova Scotia
, taking with them more than 1,000 Loyalist
civilians.
_-_general_view.jpg)
, the Heights were refortified and occupied against potential British invasion. Following that war, the fortifications were completely abandoned, and, in the later years of the 19th century, the Dorchester hills were used as a source of fill for Boston's expanding coastline.
In 1902, following revived interest in the local history, a monument was constructed on the (remaining) high ground in what is now South Boston. The large Irish population in the area was also instrumental in having March 17 (which is also Saint Patrick's Day
) named as the Evacuation Day
holiday in Suffolk County, Massachusetts
, which includes the city of Boston.
The site was added to the National Register of Historic Places
in 1966, and in 1978 came under the administration of the National Park Service
as part of Boston National Historical Park
.
American Revolutionary War
The American Revolutionary War , the American War of Independence, or simply the Revolutionary War, began as a war between the Kingdom of Great Britain and thirteen British colonies in North America, and ended in a global war between several European great powers.The war was the result of the...
that precipitated the end of the siege of Boston
Siege of Boston
The Siege of Boston was the opening phase of the American Revolutionary War, in which New England militiamen—who later became part of the Continental Army—surrounded the town of Boston, Massachusetts, to prevent movement by the British Army garrisoned within...
and the withdrawal of British troops from that city.
On March 4, 1776, troops from the Continental Army
Continental Army
The Continental Army was formed after the outbreak of the American Revolutionary War by the colonies that became the United States of America. Established by a resolution of the Continental Congress on June 14, 1775, it was created to coordinate the military efforts of the Thirteen Colonies in...
under George Washington
George Washington
George Washington was the dominant military and political leader of the new United States of America from 1775 to 1799. He led the American victory over Great Britain in the American Revolutionary War as commander-in-chief of the Continental Army from 1775 to 1783, and presided over the writing of...
's command occupied Dorchester Heights
Dorchester Heights
Dorchester Heights is the central area of South Boston. It is the highest area in the neighborhood and commands a view of both Boston Harbor and downtown.-History:...
, a series of low hills with a commanding view of Boston
Boston
Boston is the capital of and largest city in Massachusetts, and is one of the oldest cities in the United States. The largest city in New England, Boston is regarded as the unofficial "Capital of New England" for its economic and cultural impact on the entire New England region. The city proper had...
and its harbor
Boston Harbor
Boston Harbor is a natural harbor and estuary of Massachusetts Bay, and is located adjacent to the city of Boston, Massachusetts. It is home to the Port of Boston, a major shipping facility in the northeast.-History:...
, and mounted powerful cannon
Cannon
A cannon is any piece of artillery that uses gunpowder or other usually explosive-based propellents to launch a projectile. Cannon vary in caliber, range, mobility, rate of fire, angle of fire, and firepower; different forms of cannon combine and balance these attributes in varying degrees,...
s there. General William Howe
William Howe, 5th Viscount Howe
William Howe, 5th Viscount Howe, KB, PC was a British army officer who rose to become Commander-in-Chief of British forces during the American War of Independence...
, commander of the British forces occupying the city, considered contesting this act, as the cannon threatened the town and the military ships in the harbor. After a snowstorm prevented execution of his plans, Howe decided instead to withdraw from the city. The British forces, accompanied by Loyalist
Loyalist (American Revolution)
Loyalists were American colonists who remained loyal to the Kingdom of Great Britain during the American Revolutionary War. At the time they were often called Tories, Royalists, or King's Men. They were opposed by the Patriots, those who supported the revolution...
s who had fled to the city during the siege, left the city
Evacuation Day (Massachusetts)
March 17 is Evacuation Day, a holiday observed in Suffolk County and also by the public schools in Cambridge and Somerville, Massachusetts. The holiday commemorates the evacuation of British forces from the city of Boston following the Siege of Boston, early in the American Revolutionary War...
on March 17 and sailed to Halifax, Nova Scotia.
Background
The siege of BostonSiege of Boston
The Siege of Boston was the opening phase of the American Revolutionary War, in which New England militiamen—who later became part of the Continental Army—surrounded the town of Boston, Massachusetts, to prevent movement by the British Army garrisoned within...
began on April 19, 1775, when, in the aftermath of the Battles of Lexington and Concord
Battles of Lexington and Concord
The Battles of Lexington and Concord were the first military engagements of the American Revolutionary War. They were fought on April 19, 1775, in Middlesex County, Province of Massachusetts Bay, within the towns of Lexington, Concord, Lincoln, Menotomy , and Cambridge, near Boston...
, Colonial militia surrounded the city of Boston. Benedict Arnold
Benedict Arnold
Benedict Arnold V was a general during the American Revolutionary War. He began the war in the Continental Army but later defected to the British Army. While a general on the American side, he obtained command of the fort at West Point, New York, and plotted to surrender it to the British forces...
, who arrived with Connecticut militia to support the siege, told the Massachusetts Committee of Safety
Committee of Safety (American Revolution)
Many Committees of Safety were established throughout Colonial America at the start of the American Revolution. These committees started to appear in the 1760s as means to discuss the concerns of the time, and often consisted of every male adult in the community...
that cannons and other valuable military stores were stored at the lightly defended Fort Ticonderoga
Fort Ticonderoga
Fort Ticonderoga, formerly Fort Carillon, is a large 18th-century fort built by the Canadians and the French at a narrows near the south end of Lake Champlain in upstate New York in the United States...
, and proposed its capture. On May 3, the Committee gave Arnold a colonel
Colonel
Colonel , abbreviated Col or COL, is a military rank of a senior commissioned officer. It or a corresponding rank exists in most armies and in many air forces; the naval equivalent rank is generally "Captain". It is also used in some police forces and other paramilitary rank structures...
's commission and authorized him to raise troops and lead a mission to capture the fort. Arnold, in conjunction with Ethan Allen
Ethan Allen
Ethan Allen was a farmer, businessman, land speculator, philosopher, writer, and American Revolutionary War patriot, hero, and politician. He is best known as one of the founders of the U.S...
, his Green Mountain Boys
Green Mountain Boys
The Green Mountain Boys were a militia organization first established in the 1760s in the territory between the British provinces of New York and New Hampshire, known as the New Hampshire Grants...
, and militia forces from Connecticut and western Massachusetts, captured the fort
Capture of Fort Ticonderoga
The Capture of Fort Ticonderoga occurred during the American Revolutionary War on May 10, 1775, when a small force of Green Mountain Boys led by Ethan Allen and Colonel Benedict Arnold overcame a small British garrison at the fort and looted the personal belongings of the garrison...
and all of its armaments on May 10.
After George Washington
George Washington
George Washington was the dominant military and political leader of the new United States of America from 1775 to 1799. He led the American victory over Great Britain in the American Revolutionary War as commander-in-chief of the Continental Army from 1775 to 1783, and presided over the writing of...
took command of the army outside Boston in July 1775, the idea of bringing the cannons from Ticonderoga to the siege was raised by Colonel Henry Knox
Henry Knox
Henry Knox was a military officer of the Continental Army and later the United States Army, and also served as the first United States Secretary of War....
. Knox was eventually given the assignment to transport weapons from Ticonderoga to Cambridge. Knox went to Ticonderoga in November 1775, and, over the course of 3 winter months, moved 60 tons of cannons and other armaments by boat, horse and ox-drawn sledges, and manpower, along poor-quality roads, across two semi-frozen rivers, and through the forests and swamps of the lightly inhabited Berkshires
The Berkshires
The Berkshires , is a highland geologic region located in the western parts of Massachusetts and Connecticut.Also referred to as the Berkshire Hills, Berkshire Mountains, and Berkshire Plateau, the region enjoys a vibrant tourism industry based on music, arts, and recreation.-Definition:The term...
to the Boston area. Historian Victor Brooks has called Knox's feat "one of the most stupendous feats of logistics" of the entire war.
Geography and strategy
The British military leadership, headed by General William HoweWilliam Howe, 5th Viscount Howe
William Howe, 5th Viscount Howe, KB, PC was a British army officer who rose to become Commander-in-Chief of British forces during the American War of Independence...
, had long been aware of the importance of the Dorchester Heights
Dorchester Heights
Dorchester Heights is the central area of South Boston. It is the highest area in the neighborhood and commands a view of both Boston Harbor and downtown.-History:...
, which, along with the heights of Charlestown
Charlestown, Massachusetts
Charlestown is a neighborhood of Boston, Massachusetts, United States, and is located on a peninsula north of downtown Boston. Charlestown was originally a separate town and the first capital of the Massachusetts Bay Colony; it became a city in 1847 and was annexed by Boston on January 5, 1874...
, had commanding views of Boston and its outer harbor. The harbor was vital to the British, as the Royal Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...
, at first under Admiral Samuel Graves
Samuel Graves
Admiral Samuel Graves RN was a British Admiral who is probably best known for his role early in the American War of Independence.-Military career:Graves joined the Royal Navy in 1732...
, and later under Admiral Molyneux Shuldham
Molyneux Shuldham, 1st Baron Shuldham
Molyneux Shuldham was an officer of the British Royal Navy. He served for a time as colonial governor of Newfoundland.-Family and early life:...
, provided protection for the troops in Boston, as well as transportation of supplies to the besieged city. Early in the siege, the British planned to seize both of these heights, beginning with those in Dorchester, which had a better view of the harbor than the Charlestown hills. It was the leaking of this plan that precipitated events leading to the Battle of Bunker Hill
Battle of Bunker Hill
The Battle of Bunker Hill took place on June 17, 1775, mostly on and around Breed's Hill, during the Siege of Boston early in the American Revolutionary War...
.
When Washington took command of the siege in July 1775, he considered taking the unoccupied Dorchester Heights, but rejected the idea, feeling the army was not ready to deal with the likely British attack on the position. The subject of an attempt on the heights was again discussed in early February 1776, but the local Council of Safety believed the British troop strength too high, and important military supplies like gunpowder too low, to warrant action at that time. By the end of February, Knox had arrived with the cannon from Ticonderoga, as had additional supplies of powder and shells. Washington decided the time was right to act.
Fortification
Washington first placed some of the heavy cannons from Ticonderoga at Lechmere's PointLechmere Square
Lechmere Square is located at the intersection of Cambridge Street and First Street in East Cambridge, Massachusetts. It was originally named for the Colonial-era landowner Richard Lechmere, a Loyalist who returned to England at the beginning of the American Revolution. His lands were later seized...
and Cobble Hill in Cambridge
Cambridge, Massachusetts
Cambridge is a city in Middlesex County, Massachusetts, United States, in the Greater Boston area. It was named in honor of the University of Cambridge in England, an important center of the Puritan theology embraced by the town's founders. Cambridge is home to two of the world's most prominent...
, and on Lamb's Dam in Roxbury. As a diversion against the planned move on the Dorchester Heights, he ordered these batteries to open fire on the town on the night of March 2, which fire the British returned, without significant casualties on either side. These cannonades were repeated on the night of March 3, while preparations for the taking of the heights continued.
On the night of March 4, 1776, the batteries opened fire again, but this time the fire was accompanied by action. General John Thomas
John Thomas (general)
John Thomas was an American doctor and soldier from Massachusetts who became a major general in the Continental Army. He was a leader during the siege of Boston. Thomas briefly commanded the withdrawal from Canada after the unsuccessful invasion by the Continental Army. He died from smallpox...
and about 2,000 troops quietly marched to the top of Dorchester Heights, hauling entrenching tools and cannon placements. Hay bales were placed between the path taken by the troops and the harbor in order to muffle the sounds of the activity. Throughout the night, these troops and their relief labored at hauling cannon and building earthworks overlooking the town and the harbor. General Washington was present to provide moral support and encouragement, reminding them that March 5 was the sixth anniversary of the Boston Massacre
Boston Massacre
The Boston Massacre, called the Boston Riot by the British, was an incident on March 5, 1770, in which British Army soldiers killed five civilian men. British troops had been stationed in Boston, capital of the Province of Massachusetts Bay, since 1768 in order to protect and support...
. By 4 am, they had constructed fortifications that were proof against small arms and grapeshot
Grapeshot
In artillery, a grapeshot is a type of shot that is not a one solid element, but a mass of small metal balls or slugs packed tightly into a canvas bag. It was used both in land and naval warfare. When assembled, the balls resembled a cluster of grapes, hence the name...
. Work continued on the positions, with troops cutting down trees and constructing abbatis
Abatis
Abatis, abattis, or abbattis is a term in field fortification for an obstacle formed of the branches of trees laid in a row, with the sharpened tops directed outwards, towards the enemy. The trees are usually interlaced or tied with wire...
to impede any British assault on the works. The outside of the works also included rock-filled barrels that, while appearing to be a part of the defensive structure, could be rolled down the hill at attacking troops.
Washington anticipated that General Howe and his troops would either flee or try to take the hill, an action that would have probably been reminiscent of the Battle of Bunker Hill
Battle of Bunker Hill
The Battle of Bunker Hill took place on June 17, 1775, mostly on and around Breed's Hill, during the Siege of Boston early in the American Revolutionary War...
, which was a disaster for the British. If Howe decided to launch an attack on the heights, Washington planned to launch an attack against the city from Cambridge. As part of the preparations, he readied two floating batteries and boats sufficient to carry almost 3,000 troops. Washington's judgment of Howe's options was accurate; they were exactly the options Howe considered.
British reaction
Admiral ShuldhamMolyneux Shuldham, 1st Baron Shuldham
Molyneux Shuldham was an officer of the British Royal Navy. He served for a time as colonial governor of Newfoundland.-Family and early life:...
, commander of the British fleet, declared that the fleet was in danger unless the position on the heights was taken. Howe and his staff then determined to contest the occupation of the heights, and made plans for an assault, preparing to send 2,400 men under cover of darkness to attack the position. Washington, notified of British movements, increased the forces on the heights until there were nearly 6,000 men on the Dorchester lines. However, a snow storm began late on March 5 and halted any chance of a battle for several days. By the time the storm subsided, Howe reconsidered launching an attack, reasoning that preserving the army for battle elsewhere was of higher value than attempting to hold Boston.
Howe, through intermediaries, informed Washington that the city would not be burned to the ground if his troops were allowed to leave unmolested. After several days of activity, and several more of bad weather, the British forces departed Boston by sea on March 17 and sailed to Halifax, Nova Scotia
City of Halifax
Halifax is a city in Canada, which was the capital of the province of Nova Scotia and shire town of Halifax County. It was the largest city in Atlantic Canada until it was amalgamated into Halifax Regional Municipality in 1996...
, taking with them more than 1,000 Loyalist
Loyalist (American Revolution)
Loyalists were American colonists who remained loyal to the Kingdom of Great Britain during the American Revolutionary War. At the time they were often called Tories, Royalists, or King's Men. They were opposed by the Patriots, those who supported the revolution...
civilians.
Legacy
The fortifications on the Heights were maintained through the end of the war, and then abandoned. During the War of 1812War of 1812
The War of 1812 was a military conflict fought between the forces of the United States of America and those of the British Empire. The Americans declared war in 1812 for several reasons, including trade restrictions because of Britain's ongoing war with France, impressment of American merchant...
, the Heights were refortified and occupied against potential British invasion. Following that war, the fortifications were completely abandoned, and, in the later years of the 19th century, the Dorchester hills were used as a source of fill for Boston's expanding coastline.
In 1902, following revived interest in the local history, a monument was constructed on the (remaining) high ground in what is now South Boston. The large Irish population in the area was also instrumental in having March 17 (which is also Saint Patrick's Day
Saint Patrick's Day
Saint Patrick's Day is a religious holiday celebrated internationally on 17 March. It commemorates Saint Patrick , the most commonly recognised of the patron saints of :Ireland, and the arrival of Christianity in Ireland. It is observed by the Catholic Church, the Anglican Communion , the Eastern...
) named as the Evacuation Day
Evacuation Day (Massachusetts)
March 17 is Evacuation Day, a holiday observed in Suffolk County and also by the public schools in Cambridge and Somerville, Massachusetts. The holiday commemorates the evacuation of British forces from the city of Boston following the Siege of Boston, early in the American Revolutionary War...
holiday in Suffolk County, Massachusetts
Suffolk County, Massachusetts
Suffolk County has no land border with Plymouth County to its southeast, but the two counties share a water boundary in the middle of Massachusetts Bay.-National protected areas:*Boston African American National Historic Site...
, which includes the city of Boston.
The site was added to the National Register of Historic Places
National Register of Historic Places
The National Register of Historic Places is the United States government's official list of districts, sites, buildings, structures, and objects deemed worthy of preservation...
in 1966, and in 1978 came under the administration of the National Park Service
National Park Service
The National Park Service is the U.S. federal agency that manages all national parks, many national monuments, and other conservation and historical properties with various title designations...
as part of Boston National Historical Park
Boston National Historical Park
The Boston National Historical Park is an association of sites that showcase Boston's role in the American Revolution. It was designated a national park on October 1, 1974...
.