Complex sentence: The Phi Beta Kappa Society (ΦΒΚ)--the oldest honor society for the liberal arts and sciences in the United States--is widely recognized and considered as the nation's most prestigious honor society.
Split into simpler sentences: The Phi Beta Kappa Society (ΦΒΚ) is the oldest honor society for the liberal arts and sciences in the United States. It is widely recognized, and is considered as the nation's most prestigious honor society.