Complex sentence: He won the City of Chicago Championship in 1939, and the National Clay Court Championship in 1942 and 1943, and was a singles quarterfinalist at the U.S. National Championships in 1942,1943,1944, and 1945.
Split into simpler sentences: He won the City of Chicago Championship in 1939, and the National Clay Court Championship in 1942 and 1943. He was also a singles quarterfinalist at the U.S. National Championships in 1942,1943,1944, and 1945.