Complex sentence: The 1975 U.S. Open was the 75th U.S. Open, held June 19--23, at Medinah Country Club in Medinah, Illinois, a suburb northwest of Chicago.
Split into simpler sentences: The 1975 U.S. Open was the 75th U.S. Open. The golf tournament was held June 19--23,1975, at Medinah Country Club in Medinah, Illinois, a suburb northwest of Chicago.