Final answer:
Ralph Waldo Emerson, born in Boston in 1803, was a leading figure in the Transcendentalist Movement and is known for his essays like "Self-Reliance," public lectures, and his belief in individualism and self-reliance.
Step-by-step explanation:
The 19th-century American figure born in Boston in 1803, who is a central figure in the Transcendentalist Movement, is Ralph Waldo Emerson. He started his career as a minister like his father but left the profession after a personal crisis of faith. Emerson became a renowned essayist, lecturer, and poet with prominent works such as "Self-Reliance" and "The Conduct of Life." His writings, including the famous "Concord Hymn" and "Give All to Love," stress the importance of individuality and societal criticism.
Emerson's influence was bolstered by his numerous essays and public lectures, which disseminated his philosophy of transcendentalism, primarily formulated in his 1836 essay "Nature." He encouraged people to seek their spirituality within nature rather than in societal norms, urging a form of individualism and self-reliance that was reflected in the work of other Transcendentalists such as Henry David Thoreau and Walt Whitman.