Holmes supported the Missouri Compromise, and was praised by Thomas Jefferson for his pamphlet "Mr. Holmes's Letter to the People of Maine". In the letter, Jefferson thanks Holmes for a copy of this pamphlet. This pamphlet defends Holmes's position on supporting the Missouri Compromise—the admission of Maine as a free state with the admission of Missouri as a slave state, which was an unpopular position in Maine. This letter is also notable for being the first written attestation of the phrase "". Jefferson himself rejected the compromise: