The previous thoughts were quite strong. I would only add that Transcendentalism seems to be the Americanized version of the European Romantic movement with its emphasis on subjectivity and emotions. The transcendentalist thinkers really strove to place a primacy on the subjective experience as being distinct from all else. When Whitman writes “Song of Myself,” it’s Transcendental, in part, because he is not kidding around. He literally believes that the subjective experience is something that has universal application. Through the subjective, one can understand the objective. This emphasis on the emotional frame of reference to consciousness was powerful given the rapid growth of industrialization and the growing collective conformity that accompanied it in early America. The meaning of Transcendentalism in such a context brings to light how the modern definition of America was set against opposing polarities that sought to bring form and meaning to a nation that was nebulous and responsive to different forces of change.
Transcendentalism was a style of writing that emerged from the Romantic style of writing, around 1840. Just like music has different styles that are popular at different times, writing too has different styles throughout history. In America, the transcendentalists were motivated and inspired by nature, individualism (belief and celebration of oneself), a belief in universal truth that transcended (or went beyond) our mortal existences and a focus on the dignity of manual labor and personal introspection. In their writing, they focused on identifying truths of human nature, and finding great joy and wisdom in those truths, revering them as sacred and spiritual. They delighted in nature, and often found nature itself to be very spiritual and a conveyor of truth and beauty. They also focused on how every person should trust themselves, and should rejoice in all of their own beauty, instead of relying on others or the world to form their opinions or ideas.
The most famous transcendentalists are Ralph Waldo Emerson, who wrote numerous essays, the most well-known being "Self-Reliance," where he preached the importance of relying one yourself as a source of truth and wisdom. Then, Henry David Thoreau, who wrote Walden, a book on how he went to live by himself on Walden Pond, reaping truth and satisfaction from the work of his own hands.
I hope that those thoughts helped; good luck!
Transcendentalism is a philosophy based on belief that knowledge is not limited to and solely derived from experience and observation. We can contrast transcendentalism with empiricism that hold that knowledge comes only from experience.
Transcendentalism holds that reality exists only in the world of the spirit. What we observe and experience as physical world are only appearances rather than reality. The reality which exists in the spiritual world can only be known by reason, which is defined as the independent and intuitive capacity to know what is absolutely true. This philosophy is heavily influenced by the ideas of Immanuel Kant (1724-1804).
The term transcendentalism is also used for a literary and philosophical movement based on this philosophy that developed in the USA during the 1830' and 1940's. Some important figures of this movement include R.W. Emerson; Henry David Thoreau; George Ripley; Margaret Fuller; and Bronson Alcott.