The University of Missouri (Mizzou, MU, University of Missouri-Columbia or simply Missouri) is a public research university located in the state of Missouri. In 1839 the university was founded in Columbia, Missouri, as the first public institution of higher education west of the Mississippi River. The largest university in Missouri, MU enrolls 33,805 students in 20 academic colleges in the 2011-12 year. The university is the flagship of the University of Missouri System which maintains campuses in Rolla, Kansas City and St. Louis. MU is one of 34 public universities to be members of the Association of American Universities and the only one in Missouri. There are more than 262,000 MU alumni living worldwide, with almost half continuing to reside in Missouri. The University of Missouri was ranked 90th in the 2012 U.S. News & World Report among the national universities, up four spots from 2011. It is the highest-ranked public school in the state and second overall. The campus of the University of Missouri is 1,250 acres (506 ha) just south of Downtown Columbia and is maintained as a botanical garden. The historical campus is centered on David R. Francis Quadrangle, a historic district that is listed on the National Register of Historic Places, and a number of buildings on the National Register of Historic Places. In 1908, the world's first school of journalism was founded by Walter Williams as the Missouri School of Journalism. The University of Missouri Research Reactor Center is the world's most powerful university research reactor. It is one of only six public universities in the United States with a school of medicine, veterinary medicine, engineering, agriculture, and law all on one campus. The university also owns the University of Missouri Health Care system, which operates four hospitals in Mid-Missouri. Missouri's only Division I-A athletic team is known as the Missouri Tigers and compete as members of the Big 12 conference. In 2012 Missouri will compete as members of the Southeastern Conference. The school's mascot, Truman the Tiger, is named after Missourian and former U.S. president Harry S Truman. According to the NCAA, the American tradition of Homecoming was established at the University in 1911; the tradition has since been adopted nationwide.