Miss Delaware (Vincenza Carrieri-Russo) is a Gamma Sigma Sigma.
Miss Arkansas (Rachel Howells) is a Zeta Tau Alpha from University of Arkansas-Fayetteville.
Miss Kansas (Michelle Gillespie) -- heard she's a Pi Phi from SMU. Not sure though.
Miss Oklahoma (Lindsey Jo Harrington) -- think she's Greek. Can't confirm.
Miss Massachusetts (Jacqueline Bruno) from Boston University is in a sorority, I just don't know which one.
Miss Missouri (Candice Crawford) is a Pi Beta Phi at University of Missouri AND is Chase Crawford's (from Gossip Girl) sister.
And for the Miss Teen USA pagaent:
Miss South Carolina (Brittany Pjetraj) is an Alpha Delta Pi at the University of South Carolina.