Complex sentence: He also worked at Marineland and as a theater director in the U.S. Virgin Islands, where he periodically produced variety shows, featuring some of the same entertainers he previously had booked to appear on "Bozo's Circus".
Split into simpler sentences: He also worked at Marineland and as a theater director in the U.S. Virgin Islands. While living in St. Croix, Sandburg managed a theatre where he periodically produced variety shows, featuring some of the same entertainers he previously had booked to appear on "Bozo's Circus".