His a week on the Concord and Merrimack Rivers (1849) was the only other book he published in his lifetime. He reflected on a night he spent in jail protesting the Mexican-American War in the essay Civil Disobedience(1849), which would later influence such figures as M. Gandhi and M. L. King. In later years his interest in Transcendentalism waned and he became a dedicated abolitionist. His many nature writings and records of his wanderings in Canada, Maine, and Cape Cod display the mind of a keen naturalist. After his death his collected writings were published in 20 volumes, and further writings have continued to appear in print.His A Week on the Concord and Merrimack Rivers (1849) was the only other book he published in his lifetime. He reflected on a night he spent in jail protesting the Mexican-American War in the essay Civil Disobedience (1849), which would later influence such figures as M. Gandhi and M. L. King. In later years his interest in Transcendentalism waned and he became a dedicated abolitionist. His many nature writings and records of his wanderings in Canada, Maine, and Cape Cod display the mind of a keen naturalist. After his death his collected writings were published in 20 volumes, and further writings have continued to appear in print