Board Directors, University Delaware Library. Associate, since 2002. Volunteer Fogg Art Museum, Harvard University, Cambridge, 1975-1976.
Volunteer bibliographer University Virginia Library., Charlottesville, 1982-1986, board directors since 1992. Fellow Morgan Library. & Museum, New York (visiting committee manuscripts since 2008).
Member William Morris Society in the United States (president 1988-2004), Bibliographical Society United States, Tennyson Society (American representative 1986-2000), Bibliographical Society of America (director 2002-2004), William Nuthead Society, Eighteen-Nineties Society, Ticknor Society, William Morris Society (president 1992-2004), Williams Club, Grolier Club (publications committee since 1993, director 1997-2004, vice president 2004), Franklin Inn Club, Philobiblon Club, Association International des Bibliophiles, Phi Beta Kappa.