Complex sentence: He is Chairman of the Board of Midwest Gaming & Entertainment which owns casinos in Vicksburg, Mississippi, the Rivers Casino in Pittsburgh, Philadelphia, Rivers Casino in Des Plaines, Illinois, and Casino Niagara in Niagara Falls, Canada.
Split into simpler sentences: He is Chairman of the Board of Midwest Gaming & Entertainment. He owns casinos in Vicksburg, Mississippi, the Rivers Casino in Pittsburgh, Philadelphia, Rivers Casino in Des Plaines, Illinois, and Casino Niagara in Niagara Falls, Canada.