Complex sentence: Ludlow Ogden Smith, (1899--1982) was a Philadelphia socialite, married Katharine Hepburn in 1928 when she was 21 and he 29.
Split into simpler sentences: Ludlow Ogden Smith (1899--1982) was a Philadelphia socialite. He married Katharine Hepburn in 1928 when she was 21 and he 29.