Phi Delta Phi (ΦΔΦ) is an international legal honor society and the oldest legal organization in continuous existence in the United States. Predating even the American Bar Association, Phi Delta Phi was originally a fraternity; however, it became an honor society in 2012. Until its switch to becoming an honor society in 2012, Phi Delta Phi was the oldest professional fraternity in continuous existence. The fraternity was founded at the University of Michigan in 1869 "to promote a higher standard of professional ethics."