[littleowl33]

Johns Hopkins was founded in 1876. Beta Theta Pi, Alpha Chi chapter, was founded in 1877. They're the oldest, but Phi Kappa Psi was close behind in 1879. I don't think either has ever closed/recolonized.

JHU didn't start admitting women until 1970, and in 1982 both Phi Mu and Alpha Phi colonized, making them the oldest sororities on campus. I believe Alpha Phi was recolonized at least once though, so I would say Phi Mu is the oldest continuously running sorority.