Background
Thomas was born in Marshfield, Massachusetts, in 1724. He was a great-grandson of John Thomas, who came to Massachusetts in 1635 as a fourteen-year-old orphan, and the son of John and Lydia (Waterman) Thomas.
Thomas was born in Marshfield, Massachusetts, in 1724. He was a great-grandson of John Thomas, who came to Massachusetts in 1635 as a fourteen-year-old orphan, and the son of John and Lydia (Waterman) Thomas.
After studying medicine in the office of Dr. Simon Tufts of Medford, he practised for a short time at Green Harbor.
After his study he went to Kingston, Massachussets, where he resided for the rest of his life except when absent on military duty.
On March 1, 1746, he was authorized by Governor Shirley to practise "Chirurgery and Medicine" in the army and in the following year he served under General Waldo in Nova Scotia. In February 1755 he was commissioned lieutenant and surgeon's mate and empowered to enlist volunteers in the province; later the same year he participated in Winslow's descent upon Acadia; and in 1759-60 he served in Nova Scotia and in the expedition dispatched to Canada under Amherst. During the next fifteen years he was principally occupied in practising his profession at Kingston.
In 1770 Governor Hutchinson appointed him a justice of the peace. At the outbreak of the Revolution he was chosen (February 9, 1775) by the Provincial Congress of Massachusetts one of five general officers, on May 19 was commissioned lieutenant-general of the state troops, and on June 22, elected brigadier-general by the Continental Congress. Learning that his Continental commission was antedated by those of William Heath and Seth Pomeroy who had previously served under his command in the Massachusetts forces, he decided to resign, but Washington, who held him in high esteem, appealed to him in an earnest and eloquent letter to subordinate personal considerations to the common interest, and Thomas consented to remain.
During the winter of 1775-76, he was in command at Roxbury, the most important post in the American siege lines. Washington directed him to occupy Dorchester Heights, overlooking both the harbor and town of Boston, and on the night of Mar. 4, accompanied by about 3, 000 picked men, several pieces of artillery, and 360 ox teams laden with entrenching materials, he seized and fortified this strategic site. Howe planned an attack, but a violent storm delayed the movement and enabled Thomas to render his position impregnable. As a result the British were obliged to evacuate Boston.
In the meantime disaster had overtaken the American arms in Canada. In a futile assault upon Quebec on the night of December 31, 1775, Montgomery had been killed and Arnold had been wounded; sickness and desertion were decimating the Patriot ranks. Chosen by the Continental Congress to take charge of this discouraging situation, Thomas was promoted to the rank of major-general on March 6, 1776, and ordered north. Arriving before Quebec on May 1, he found that of a force of some 1, 900 men, only about 1, 000 were fit for duty; there were only 150 pounds of powder and less than a week's provisions; a large British fleet laden with supplies and reenforcements was approaching Quebec. Thomas summoned a council of war at which it was unanimously decided to retreat, and the army accordingly fell back to Sorel. Shortly thereafter Thomas died of smallpox and was buried near the fort at Chambly.
John Thomas was a man of commanding presence, six feet tall and well proportioned.
He had married in 1761 Hannah Thomas of Taunton, daughter of Nathaniel Thomas, who although bearing the same name as her husband was not related to him. They had two sons and a daughter.
