Complex sentence: McCain and his wife, the former Erin Purifoy Sandlin (1918-1989), who wed in 1937, had ten children, including his namesake son and, later, grandson.
Split into simpler sentences: McCain and his wife, the former Erin Purifoy Sandlin (1918-1989), wed in 1937. They had ten children, including his namesake son and, later, grandson.