Complex sentence: The 1963 U.S. Open was the 63rd U.S. Open, held June 20--23 at The Country Club in Brookline, Massachusetts, a suburb southwest of Boston.
Split into simpler sentences: The 1963 U.S. Open was the 63rd U.S. Open. The golf tournament was held June 20--23,1963, at The Country Club in Brookline, Massachusetts, a suburb southwest of Boston.