Ralph Waldo Emerson was an American essayist, lecturer, and poet who led the transcendentalist movement of the mid-19th century. Born in 1803 in Boston, Massachusetts, Emerson studied at Harvard and became a minister in 1829. However, he left the ministry to pursue a career in writing and public speaking. His essays, such as 'Self-Reliance' and 'Nature,' promoted individualism, self-improvement, and the beauty of nature. Emerson's ideas greatly influenced American thought and literature, earning him a prominent place in the intellectual history of the United States.