MJB you are correct about the name. From the official <A target="_blank" HREF=http://www.ussconstitution.navy.mil>website</A>
Aug. 19 - The CONSTITUTION's historic fight with HMS GUERRIERE takes place some 600 miles east of Boston on the afternoon of August 19, 1812. After an hour of inconclusive maneuvering and shooting, the two settle down to a short-range slugfest. After 20 minutes the Briton's mizzenmast falls, and a short time later both her remaining masts go overboard. At some point in the battle, someone reportedly sees a British shot bounce off the CONSTITUTION's side, and shouts, "Huzzah! Her sides are made of iron!"-and so is born the nickname "OLD IRONSIDES."