Harvard University is a private Ivy League research university in Cambridge, Massachusetts, whose history, influence and wealth have made it one of the most prestigious universities in the world. Established in 1636 by the Massachusetts legislature and soon thereafter named for JohnHarvard , Harvard is the United States' oldest institution of higher learning, and the Harvard Corporation is its first chartered corporation. Although never formally affiliated with any denomination, the early College primarily trained Congregationalist and Unitarian clergy. Its curriculum and student body were gradually secularized during the 18th century, and by the 19th century Harvard had emerged as the central cultural establishment among Boston elites. Following the American Civil War, President Charles W. Eliot's long tenure transformed the college and affiliated professional schools into a modern research university; Harvard was a founding member of the Association of American Universities in 1900. The undergraduate college became coeducational after its 1977 merger with Radcliffe College. The University is organized into eleven separate academic units—ten faculties and the Radcliffe Institute for Advanced Study—with campuses throughout the Boston metropolitan area: its 209-acre main campus is centered on Harvard Yard in Cambridge, approximately 3 miles northwest of Boston; the business school and athletics facilities, including Harvard Stadium, are located across theCharles River in the Allston neighborhood of Boston and the medical, dental, and public health schools are in the Longwood Medical Area.