Maj. Samuel Lawrence fought at the Battle of Bunker Hill under Henry Farwell. Samuel served in the army for 3 and half years from 1775 to 1778, and rose within the U.S. Army to the rank of major. While in the army he married Susanna Parker on July 22, 1777. He was adjutant under General John Sullivan in the Battle of Rhode Island and served there until he retired from service in 1778. After the war, Lawrence returned to Groton, where he settled as a farmer. In 1793, he helped to found Groton Academy (now Lawrence Academy at Groton).
He was the patriarch of Boston Brahmin Lawrence family. His sons, William (1783–1848), Abbott (1792–1855), and Amos (1786–1852), were all influential in United States history. He was also the father of Samuel (1801) who was a business partner with his brother William, and Luther Lawrence (1778–1839) who was Mayor of Lowell, MA 1838–39. Luther died on April 17, 1839 when he fell into a wheel pit while showing a visitor around his mill.
^"Extracts From The Diary And Correspondence Of The Late Amos Lawrence; With A Brief Account of Some Incidents in his Life" Edited By His Son, William R. Lawrence M.D., published by Gould And Lincoln, BOSTON 1855.