Ralph Waldo Emerson (May 25, 1803 - April 27, 1882) was an American essayist, lecturer, and poet who led the Transcendentalist movement of the mid-19th century. He was seen as a champion of individualism and a prescient critic of the countervailing pressures of society, and he disseminated his thoughts through dozens of published essays and more than 1,500 public lectures across the United States.