Complex sentence: Robert Ellis Cahill (November 25,1934-June 19,2005) was the author of more than three dozen books on New England history and folklore, as well as on scuba diving, shipwrecks and pirates.
Split into simpler sentences: Robert Ellis Cahill (November 25,1934-June 19,2005) was a folklorist. He the author of more than three dozen books on New England history and folklore, as well as on scuba diving, shipwrecks and pirates.