THOMAS, JOHN. (1724–1776). Continental general. Massachusetts. Born in Marshfield, Massachusetts, John Thomas studied medicine under Dr. Simon Tufts in Medford. Thomas began his military career on 1 March 1746, when Governor William Shirley appointed him as a surgeon's mate to the garrison at Annapolis Royal. He served the next year under General Samuel Waldo in Nova Scotia, and returned to the region in 1755 as a lieutenant and again in 1759–1760 as colonel of a provincial regiment. In the summer of 1760 he commanded a provincial regiment in Sir Jeffrey Amherst's advance down Lake Champlain, and led the left wing of Colonel William Haviland's detachment that joined in the capture of Montreal on 8 September 1760. Thomas spent the next 15 years engaged primarily in the practice of medicine at Kingston, Massachusetts. When the revolutionary movement started, he joined the Sons of Liberty. As the siege of Boston began, the Massachusetts Provincial Congress needed to bring order to the army, so it appointed this experienced senior officer as colonel of a regiment raised in Plymouth County, and on 25 May 1775 named him lieutenant general (second-in-command) of all Massachusetts troops. He commanded the right wing of the army at Roxbury, facing the British across Boston Neck.
In his fiftieth year, he stood six feet tall, had a distinguished face, and a commanding presence. When Congress prepared its first list of eight brigadier generals (22 June 1775), it did not fully consider military seniority at the state level, and appointed the mediocre William Heath and the superannuated Seth Pomeroy over the capable Thomas. On 10 July, in his first detailed report to Congress about conditions around Boston, General George Washington hinted broadly that Congress should remedy the situation. When Pomeroy declined his appointment, Congress made Thomas the senior brigadier general. Meanwhile, Thomas had conducted himself with decorum and had demonstrated his superiority as a military leader. Washington gave him the job of occupying Dorchester Heights, and on the evening of 4 March 1776 Thomas led 3,000 men across Dorchester Neck to take possession of this critical hill overlooking Boston Harbor. The successful completion of this critical operation gained him even higher esteem in the eyes of Washington and the Boston army.
On 6 March 1776 Thomas was promoted to major general and ordered north, where disaster had already struck during the invasion of Canada. He left Roxbury on 22 March, reached Albany on the 28th, and on 1 May took command of the American army around Quebec. The very next day he got the bad news that a British relief expedition was coming up the St. Lawrence River, and on 6 May he had to start a demoralized and disorganized retreat toward Montreal. He contracted the smallpox that was decimating his army and died on 2 June at Sorel.
Coffin, Charles. The Life and Services of Major General John Thomas. New York: Egbert, Hovey, and King, 1844.
Thomas Papers. Boston: Massachusetts Historical Society.
revised by Harold E. Selesky