Presbyterian College (Clinton, SC) is the smallest Division I FCS (Football Championship Subdivision, formerly Division IAA) school, with 1200 undergraduates. The smallest Division
http://wiki.answers.com/Q/Which_school_in_division...

Rice University is the smallest NCAA Division 1A
http://www.chacha.com/question/whatistheenrollm...

I think some of the schools on the smaller side include: Duke. The Academies (Army, Navy, Air Force) Wake Forest.
http://answers.yahoo.com/question/index?qid=200710...

(Out of curiosity, why do you ask?) Out of natural numbers, the answer is trivially 0. So trivially that clearly you actually care about positive integers instead. Out of those, the
http://www.quora.com/Mathematics/Whatisthesmall...
