Born in Deerfield, Massachusetts, he is remembered as a journalist and author, whose father, Hosea Hildreth, became a Unitarian minister after he was disowned by Congregationalists when he persistently exchanged pulpits with Unitarian ministers. He became a principle editor of the New York Tribune after he wrote America's first antislavery novel—The Slave: or Memoirs of Archy Moore—and an antislavery book, Despotism in America. In his writing he emphasized the negative effects of slavery on the South. His wife, Caroline, supported the family for eight years during which he researched and wrote a respected irreverant story of the Founders entitled History of the United States of America (1849-1852).