Rev. Barry Andrews, Minister Emeritus of the Unitarian Universalist Congregation at Shelter Rock on Long Island, New York Transcendentalism was essentially a religious movement that emerged from Unitarianism in the middle decades of the 19th century. I view the Transcendentalists—Emerson, Thoreau, and Margaret Fuller among them—as living voices whose writing is addressed as much today as it was in their time, to spiritual seekers such as ourselves.