An unsuccessful businessman, he became interested in politics and was a member (1765-74) and clerk (1766-74) of the lower house of the Massachusetts legislature. As colonial resistance to British laws stiffened, Adams spoke for the discontented and replaced James Otis as leader of the extremists. He drafted a protest against the Stamp Act in 1765 and was one of the organizers of the non-importation agreement (1767) against Great Britain to force repeal of the Townshend Acts. He drew up the Circular Letter to the other colonies, denouncing the acts as taxation without representation. More important, he used his able pen in colonial newspapers and pamphlets to stir up sentiment against the British. His polemics helped to bring about the Boston Massacre. With the help of such men as John Hancock he organized the revolutionary Sons of Liberty and helped to foment revolt through the Committees of Correspondence. He was the moving spirit in the Boston Tea Party. Gen. Thomas Gage issued (1775) a warrant for the arrest of Adams and Hancock, but they escaped punishment and continued to stir up lethargic patriots. Samuel Adams was a member (1774-81) of the Continental Congress, but after independence was declared his influence declined; the "radical" was replaced by more conservative leaders, who tended to look upon Adams as an irresponsible agitator. He later served (1794-97) as governor of Massachusetts.
See writings ed. by H. A. Cushing (4 vol., 1904-08, repr. 1968); biographies by J. C. Miller (1936, repr. 1960), S. Beach (1965), W. V. Wells (2d ed. 1969), and N. B. Gerson (1973).