Complex sentence: Despradelle's most famous project was the unrealized "Beacon of Progress" ("the Beacon") a towering monument that he intended for the site of the Columbian Exposition of 1893 in Chicago, Illinois.
Split into simpler sentences: Despradelle's most famous project was the unrealized "Beacon of Progress" ("the Beacon"). The Beacon was a towering monument that he intended for the site of the Columbian Exposition of 1893 in Chicago, Illinois.