klk112 at Carnegie Mellon
Paula M in the 60s
These two stories chronicle locals at schools where the rest of the chapters are already National. However, there are cases where all the locals at a school affiliate with an NPC at the same time. Recently (2009 I think?), Sacred Heart did this, and glittergal1985 is a Theta Phi Alpha alumna who was a senior when her chapter was installed.
Also, Sewanee (University of the South) has one NPC, one local that is seeking NPC affiliation (Kappa Omega), and 7 locals. Perhaps you could get in touch with Kappa Omega about their experiences.
Pepperdine's locals went NPC in the late 90s and I believe PeppyGPhiB was part of the founding class, not sure if she was part of the local though.
Wake Forest's locals went NPC sometime in the 80s.