Complex sentence: The popularization begun by the World Columbian Exposition was increased by the Louisiana Purchase Exposition in St. Louis in 1904 and the commissioner of architects selected Franco-American architect Emmanuel Louis Masqueray to be Chief of Design of the fair.
Split into simpler sentences: The popularization begun by the World Columbian Exposition was increased by the Louisiana Purchase Exposition in St. Louis in 1904. The commissioner of architects selected Franco-American architect Emmanuel Louis Masqueray to be Chief of Design of the fair.