Thornton was born in Ireland about 1714. Approximately 4 years later, his Scotch-Irish parents emigrated with their family to America, settling first at Wiscasset, in present Maine, and then near Worcester, Mass. Young Thornton, after attending common schools, undertook the study of medicine with a local doctor. In 1740 he began what proved to be a thriving practice in the Scotch-Irish town of Londonderry (present Derry Village), N.H. Five years later, as a surgeon in the New Hampshire militia during King George's War (1740-48), he participated in the British expedition from New England that captured Louisbourg, the French fortress in Nova Scotia.
By 1758 Thornton was representing Londonderry in the colonial legislature and stayed there until 1775. During the long interim, about 1760 he married and began a family of five; and throughout the period he figured prominently in New Hampshire politics and Revolutionary activities. In 1775-76 he held the offices of president of the provincial assembly and constitutional convention, chairman of the council of safety, and member of the upper and lower houses of the legislature, as well as speaker of the former. Although he did not enter Congress until November 1776, or 3 months after the formal signing of the Declaration, he was granted permission to affix his signature.
About a year later, Thornton left Congress to devote his time to his duties as associate justice of the State Superior Court. Despite a lack of legal education, he had acquired this position in 1776. He held it until 1782, some 2 years after he retired from his medical practice in Londonderry and settled on a farm he purchased near Merrimack, N.H. Later, in 1784-86, he completed a tour in the State senate. He spent his last years farming and operating a ferryLutwyche's (later Thornton's) Ferryacross the Merrimack River.
Thornton died in 1803 at about the age of 89 while visiting his daughter in Newburyport, Mass. His grave is in Thornton's Ferry Cemetery, near the site of his Merrimack home.
Drawing: Oil, date unknown, by an unknown artist, New Hampshire Historical Society, Concord.
Last Updated: 04-Jul-2004