Horace Mann was born on May 4, 1796, in Franklin, Massachusetts, to a poor farming family. He was raised as a Calvinist, though he later rejected the doctrines of the faith and eventually favored Unitarianism. His father died when he was 13 years old. Financial limitations were such that, until the age of 15, Mann was only able to attend school 8-10 weeks per year. Nevertheless, his dedicated use of the small Franklin Town Library and attendance at Williams Academy in Wrentham supplied him with sufficient knowledge to enter Brown University in 1814. He graduated as valedictorian in 1819.
Two years later, in 1821, Mann was admitted as one of about 30 students to the law school of Judge James Gould at Litchfield; he was admitted to the Norfolk County bar in December 1823. Mann lived in Dedham, Massachusetts, where he worked as an attorney until his election as a State Representative in 1827. He used this political position to advocate civil and religious liberty, temperance, and education. While achieving public and professional eminence, he also experienced several tragic events during the next 10 years. His marriage to Charlotte Messer (the daughter of Brown University President, Dr. Asa Messer) in 1830 lasted only two years before her death of tuberculosis. In 1833, the grieving Mann moved from Dedham to Boston, following which he suffered the loss of his mother and two close friends (Silas Holbrook and his father-in-law, Dr. Messer).
In Boston, he lived at the boarding house of preacher James Freeman Clarke's mother, where he met Unitarian minister Jared Sparks and the Peabody sisters, Elizabeth and Mary. He married Mary Tyler Peabody in 1843. From 1833 to 1837, Horace Mann served on the state senate. After voting to establish the first Massachusetts Board of Education, he became its first secretary in 1837. In this capacity, he profoundly influenced the educational system within Massachusetts and the rest of the United States.
Horace Mann wrote 12 annual reports, in which he propounded (among other subjects) the economic value of having an educated populous, the right of every child to an education, and the value of funding education through taxes. Among the many educational reforms attributed to Mann are the extension of the school year to a minimum of six months, the establishment of normal schools for the education of teachers, an increase in government financial support for public schools, and the establishment of free school district libraries. His advocacy of non-sectarian religious education caused discontent among both advocates of secularized education and Christian conservatives.
In 1848, Mann accepted John Quincy Adams' former position in the United States House of Representatives. During his congressional service, he continued to interest himself in educational matters and maintained a strong anti-slavery position. In collaboration with Edward Everett, he helped implement the Prussian educational system in Massachusetts in 1852.
From 1853 until his death, Horace Mann served as the first President of Antioch College in Yellow Springs, Ohio. Antioch, founded in 1852, had relatively high academic standards and offered equal instruction to members of both sexes. One of the teachers employed by Horace Mann, Rebecca Pennell (Mann's niece), is considered to have been the first female faculty member to receive equal pay with her male colleagues. In addition to his role as President, Mann also instructed courses in economics, theology, and philosophy. For the entire length of his service, the college suffered from various troubles, resulting in part from sectarian disagreements between administrative bodies. Sickness prompted Horace Mann to cease work at the college. He gave his last public speech to Antioch's graduating class of 1859, which included the often quoted line: "I beseech you to treasure up in your hearts these my parting words: Be ashamed to die until you have won some victory for humanity." He died two months later on August 2, 1859.