1774 through the Revolution, member of Northampton's committee of safety. In 1776 he was elected to the Massachusetts General Court and held the post of county attorney for Hampshire County for 24 years. Declined a position on the state supreme court in 1783..

Constitutional Convention,

• Favored a strong central government.
• He wanted a system the same rank and mode of election to both houses of Congress, but voted for equal representation in the Senate and proportional in the House.
• Because of illness in the family he missed signing the of the Constitution, but he campaigned strongly for ratification of the Constitution in Massachusetts.

Caleb Strong was one of Massachusetts first U.S. senators in 1789.

Caleb Strong, as the Federalist candidate, defeated Elbridge Gerry to become Governor of Massachusetts in 1800, won reelection until 1807. In 1812 he regained the governorship until 1816.

During the War of 1812 Strong withstood pressure from the Secretary of War to order part of the Massachusetts militia into federal service. Strong opposed the war.

Caleb Strong died on November 7, 1819, and was buried in the Bridge Street Cemetery in Northampton.