Complex sentence: Bronx Zoo director William Hornaday saw the exhibit as a valuable spectacle for his visitors, and was encouraged by Madison Grant, who a decade later became prominent as a racial anthropologist and eugenicist.
Split into simpler sentences: Bronx Zoo director William Hornaday saw the exhibit as a valuable spectacle for his visitors, and was encouraged by Madison Grant. A decade later, Grant became prominent as a racial anthropologist and eugenicist.