Formal organization in the United States (although many churches did not join the association for fear it would impede their freedom) commenced in 1820, and in 1825 became the American Unitarian Association (AUA). Unitarians have always been involved in essentially religious but scrupulously non-sectarian, humanitarian social action. Unitarians were involved in the struggle against slavery and were important to the success of the Abolitionist movement. Unitarians and Universalists have pioneered in human welfare causes and movements; they include Susan B. Anthony in woman's suffrage, Dorothea Dix in prison reform and the treatment of the mentally ill, and Horace Mann in the cause of public education. Unitarianism has never attracted a large number of adherents, but its liberal influence in general religious thought has been significant. Also it has greatly promoted and enhanced education and the establishment of libraries and schools.