I had no idea that Zeta Psi had a chapter at Oxford. Very cool.
Jack, if you'd like to learn more about American fraternities you might stop by the NIC (North-American Interfraternity Conference) website.
http://www.nicindy.org/
The member fraternities and their own websites are listed here:
http://www.nicindy.org/information/N..._fraternities/
Phi Delta Theta and Kappa Sigma both left the NIC but their websites are:
http://www.phideltatheta.org/
http://www.kappasigma.org/
Best of luck to you!