Who Was John Thomas? 


Image from the collections of the Massachusetts Historical Society.

Image from the collections of the Massachusetts Historical Society.

In the middle of our neighborhood sits Thomas Park, surmounted by the elegant Dorchester Heights Monument.  We know, if we read the signs, that this oval is named for General John Thomas, who oversaw the fortification of the Heights in March 1776.  But who was John Thomas?  Why was he overseeing the operation?  And what happened afterward?

Thomas had been a doctor in Kingston for fifteen years when he heard the news of Lexington and Concord;  he immediately left his wife and three children to join the American forces around Boston.  He came with great military experience—in fact, more than any other American-born officer in the fledgling Continental Army.

At age 22, in 1746, he had served as a surgeon and a junior in the Nova Scotia campaign; when he was 31 he was both a company commander and a surgeon in the siege of the French fortress at Beauséjour, on the Chignecto isthmus connecting Nova Scotia to New Brunswick.   After seizing the fort (and renaming it Fort Cumberland), Thomas was part of the force that rousted the Acadians from Nova Scotia.  By age 35 he was a Colonel, recruiting troops in Boston and Plymouth for Sir Jeffrey Amherst’s campaign to take Montreal in 1760.  In eight years, Thomas had fought in eight campaigns, becoming an experienced combat officer under the supervision of British officers.  He returned home after the war, married Hannah Thomas—no relation, but the daughter of Lieutenant Colonel Nathaniel Thomas of Plymouth, who had died in the 1745 siege of Louisbourg.

John and Hannah Thomas settled in Kingston, where their daughter and two sons were born.  John Thomas practiced medicine, owned a small trading boat, invested in local industries, and served on the Board of Selectman, as town moderator, assessor, and justice of the peace.  Then he heard the news of Lexington and Concord, and came to the scene, where he was put in charge of the forces in Roxbury.   He made his headquarters in the First Church parsonage, on a hill overlooking Boston Neck, the only road in and out of Boston (now Washington Street).  The house still stands—the Dillaway-Thomas House, in Roxbury Heritage State Park.  While much of the army camped in Cambridge, this southern wing was crucial to keeping the British army besieged.  Thomas’s skill as both a commander and medical officer showed.

Thomas’s “merits in the military way have surprised us all,” James Warren wrote to John Adams.

“I can’t describe to you the odds between the two camps in Cambridge and Roxbury”.  The camp in Cambridge, in and around Harvard, was “spiritless, sluggish, confused, and dirty,” while Thomas’s camp in Roxbury “spirited, active, regular and clean.”  Thomas himself “appeared with the dignity and abilities of a General.”

The Massachusetts Committee of Safety commissioned him a Lieutenant General in May.   He oversaw the fortification of Roxbury to prevent the British from either coming out by land, or taking Dorchester Neck.  The British attack at Bunker Hill on June 17 was just the first part of a longer campaign to clear the rebel camps from Cambridge and Roxbury—but the colonists inflicted so much damage in Charlestown the British did not venture further.

But while Thomas was fortifying Roxbury, and the Cambridge forces were holding the British in Charlestown, Congress acted to turn these militia men into a Continental Army.  They commissioned George Washington as commander in chief, and also named eight brigadier generals to assist him.  When Washington arrived in early July, he brought with him commissions for eight brigadier generals.  Thomas was not on the list, but two men he commanded were.  This snub was apparent, as by now the other officers regarded Thomas as one of the cause’s most capable officers.  Abigail Adams worried that “If Thomas resigns, all his officers resign,” and Washington wrote Congress that the “much esteemed” Thomas would find it difficult to take orders from men who were his subordinates.

Though Thomas said nothing, other than that if he resigned from the army, he would come back to serve as a volunteer, Washington and the Massachusetts delegates to Congress secured him a commission as brigadier general.  He continued in command of the Roxbury forces, preventing the British from leaving by way of Boston Neck in 1775 and early 1776.

On the evening of March 4, Thomas led three thousand men from Roxbury to secure and fortify Dorchester Heights.  He had 360 teams of oxen carrying cannon as well as lumber to build defense works.  Then as now, the ground was frozen;   the men could not dig, but had to cut down the fruit trees in the orchards of Dorchester and Roxbury to make their barricades.  They began at eight in the evening; by ten their fortifications could withstand musketry and grapeshot; by dawn they had placed the cannon and had the British fleet in range.  Though General William Howe ordered an attack on March 5, a storm dissipated it, and the British began their process of evacuation.

Though Thomas would be crucial to the British evacuation, he would not stay long in Roxbury.  With the British army pinned down in Boston in 1775, Congress had authorized an invasion of Canada; Robert Montgomery had taken Montreal in November, and Benedict Arnold led a force to take Quebec.  The Quebec campaign failed.  Robert Montgomery died and Arnold was badly wounded in the siege; Congress commissioned Thomas a major general on March 6 and ordered him north to lead the campaign.  He sent his son John, who had run off from Kingston to join his father in Roxbury and Dorchester Heights, back to Kingston and made his way to Canada.

Congress also sent a delegation including Benjamin Franklin and Father John Carroll—later the first American Catholic Bishop—to bring the Canadians into the cause.  They failed, and Thomas found the American forces outside Quebec badly organized.  More than nine hundred of the two-thousand American s were ill, many with smallpox, and only five hundred were fit for duty, as they tried to besiege a city of five thousand defended by sixteen hundred soldiers, and a British fleet was making its way up the St. Lawrence.   Thomas ordered a retreat on May 5, and led his suffering army—those not too ill to travel—up the St. Lawrence and then the Richelieu River toward Lake Champlain.  There at Fort Chambly he fell ill on May 19, just two months after the evacuation of Boston.  Though Dr.  Thomas had treated many cases of smallpox, he had neither contracted the disease nor been inoculated.  Now he had it, and on June 2 died.  That same day he was buried in an unmarked grave with other soldiers struck by the virus.

The army lost one of its most capable officers—an officer with more military experience than Washington.  His memory lives on in South Boston.


Robert J. Allison is president of the South Boston Historical Society, and chairs the History Department at Suffolk University.  His most recent book is The American Revolution:  A Concise History.