Chartered in 1855 to apply scientific principles to farming, The Pennsylvania State University system is one of the largest state university systems in the US. Penn State has an enrollment of approximately 80,400 students; 8,000 of them are graduate students. It offers 160 undergraduate and 150 graduate programs at about 20 campuses. The school's oldest and largest campus, with about half of the system's undergraduate students, is at University Park in central Pennsylvania. Other sites include the College of Medicine in Hershey, Pennsylvania, and the Dickinson School of Law in Carlisle, Pennsylvania.