Complex sentence: He attended public schools in New York, winning an art prize upon his graduation from high school, and at an exhibit of the work of some of the great masters at the New York World's Fair in 1939 was very impressed by Rembrandt's portraits.
Split into simpler sentences: He attended public schools in New York, winning an art prize upon his graduation from high school. At an exhibit of the work of some of the great masters at the New York World's Fair in 1939 was very impressed by Rembrandt's portraits.