The third installment of the UU History Film Series talks about the development of Unitarianism in America from 1620 through the death of Theodore Parker in 1860. It discusses the early fractures between religious liberals and Congregationalists in Colonial America, the effect of Joseph Priestley’s immigration and William Ellery Channing’s role in the formation of the American Unitarian movement, and the final split between the Unitarians and the Trinitarian Congregationalists in the 1820s from both a theological and a legal perspective. It revisits the Arian/Socinian fracture that played out here as well and the Transcendentalism of Ralph Waldo Emerson, Margaret Fuller, and Theodore Parker. It talks about the key role Fuller played in moving Transcendentalism out from a niche movement in Concord to the driving force behind Unitarianism. Finally, It discusses the role Theodore Parker played in advancing Unitarianism beyond its traditional Bible-centered roots and his role in some of the great social justice issues of the day, especially the abolition of slavery.