Butler College is one of six residential colleges that comprise Princeton University. As of the opening of Butler's dormitories and common spaces in 2009, it became a full four-year residential college. Butler is a liberal arts college offering a variety of programs, with most students beginning specialized studies after their sophomore year. The school houses about 500 freshmen and sophomores, and 100 juniors and seniors as well as several graduate students. A wide variety of clubs, activities and student life opportunites are available. Princeton University is a private, Ivy League research university founded in 1746.