John O'Connell has long been one of our leading thermodynamicists in the field of electrolyte solutions, and I had the privilege of working with him on this subject for several years during the period that we overlapped at the University of Virginia (1988-1994). In this talk, I will briefly review John's seminal contributions in this field, as well as our joint work, and then review some of my group's recent efforts to develop highly accurate forcefields for molecular simulation of water and aqueous solutions.