The LDS Family History Center has many films and books on Puerto Rico, including slave registers for 1867-1876. Check their online catalog at familysearch.org/ for catalog numbers. Most are in Spanish, but lists of names are simply that... lists of names.

Several resources are also available at genealogyforum.rootsweb.com/gfaol/resource/Hispanic/ (This is the internet connection to the Golden Gate Genealogy Forum at AOL; you don't have to be a subscriber to AOL to use it.)

Further, you may wish to contact the Puerto Rican/Hispanic Genealogical Society at PO Box 260118, Bellerose NY 11426, or e-mail them at prhgs@yahoo.com/ They also have a very informative website (including some data!) at www.rootsweb.com/~prhgs

Happy Hunting!