Oklahoma State University?Stillwater (also referred to informally as Oklahoma State, OKState, O-State and OSU) is a land-grant, sun-grant, coeducational public research university located in Stillwater, Oklahoma, USA. OSU was founded in 1890 under the Morrill Act. Originally known as Oklahoma Agricultural and Mechanical College (Oklahoma A&M), it is the flagship institution of the Oklahoma State University System. Official enrollment for the fall 2010 semester system-wide was 35,073, with 23,459 students enrolled at OSU-Stillwater. Enrollment shows the Freshman class of 2012 was the largest on record with 4,298 students. OSU is classified by the Carnegie Foundation as a research university with high research activity.