In terms of worldview thinking Romanticism / Transcendentalism was the mystical new agey subjectivistic godless ying to the rationalistic objectivistic godless yang of Deistic Unitarianism. Romanticism / Transcendentalism flexed its muscle in New England with the take over of Harvard from the Deistic Unitarians circa 1840′s.
Whereas Unitarianism posited some kind of rational divine order that could be read via the use of autonomous right reason of a deistic natural law, Romanticism / Transcendentalism had a kind of Hegelian pantheistic feel to it as it thumped the idea of connecting with the divine oversoul in all of us. Unitarianism was very rationalistic oriented while Transcendentalism / Romanticism was given to the feelings and the senses.
Epistemologically speaking, Deistic Enlightenment Unitarianism insisted that man could know via reason discovering self-evident truths. Transcendentalism / Romanticism however made the Epistemological move to intuition as the basis of knowing. Rationalism gaves us the godless outward look, while Romanticism / Transcendtalism gives us the godless inward look. Ontologically speaking, the god concept for Deistic Enlightenment Unitarianism remained objective, however ontology for the Transcendentalist / Romanticism was not the god outside but the god in all of us. The American Transcendental movement’s philosophical pillar was that the individual is identical with the world, and that world exists in unity with God. Through this logic, it followed that the individual soul is one with God. Anthropologically speaking, Romanticism / Transcendentalism believed that man should be primarily thought of in terms of spirit or the divine spark. They believed that man was inherently good and that man had only to be educated into his inherent goodness.
As Romanticism / Transcendentalism gained a foothold in American culture one consequence was the rise of radial abolitionism. The Romanticist /Transcendentalist worldview, believing that all men share equally in their god quotient therefore believed that all men were perfectly equal and that the power of the State should be used to insure that all men were forcefully given their equality. Interestingly enough, Romanticism / Transcendentalism, as it informed the radical abolitionists worldview, served as one of the factors that set the Northern Yankee armies marching.
The power of Romanticism / Transcendentalism dissipated and eventually the rise of Darwinism as a worldview began to account for social order mythology that animated the West. Somewhere around the 1930′s – 1940′s the power of Existentialism as the guiding motif for the West began to pick up steam.
America has had basically 4 or 5 worldviews. Calvinism, Rationalistic Unitarianism, Romanticism / Transcendentalism, (which also explains the rise of the Jacksonian Democratic Revolution here), Social Darwinism, and Existentialism. Some would argue that currently we are in a kind of Nihilistic worldview, though Nihilism, what is styled as “post-modernism,” could also be argued as merely subsequent extensions of Existentialism.
Of course these matters are not always clear cut in terms of the exact dates in which they are hegemonic. For example, even though we are in kind of a Nihilistic mode right now, the relative rationalism of Darwinism still reigns supreme in the hard sciences. Also keep in mind that in the end there are only two worldviews. Biblical Christianity vs. some variant of Humanism.