Phi Sigma Kappa (FSK), colloquially known as Phi Sig or PSK, is a men's social and academic fraternity with approximately 90 active chapters and colonies in North America. Most of its first two dozen chapters were granted to schools in New England and Pennsylvania, therefore its early development was strongly Eastern in character, eventually operating chapters at six of the eight Ivy League schools as well as more egalitarian state schools. It later expanded to the South and West.