The Geisel School of Medicine at Dartmouth is the graduate medical school of Dartmouth College in Hanover, New Hampshire. The fourth oldest medical school in the United States, it was founded in 1797 by New England physician Nathan Smith. It is one of the seven Ivy League medical schools. Several milestones in medical care and research have taken place at Dartmouth, including the introduction of stethoscopes to U.S. medical education (1838), the first clinical x-ray (1896), and the first intensive care unit (ICU) in the United States (1955).