Complex sentence: By this time, Provincetown had become a refuge of artists and expatriates returned from war-torn Europe and was firmly established as "The Biggest Art Colony in the World" (Boston Globe, 8/8/16).
Split into simpler sentences: By this time, Provincetown had become a refuge of artists and expatriates returned from war-torn Europe. The town was firmly established as "The Biggest Art Colony in the World" (Boston Globe, 8/8/16).