Complex sentence: He joined "The Guardian" in 1968, and later became the American correspondent for "The Observer" (and occasional guest commentator on National Public Radio's "Weekend Edition Saturday") and parliamentary sketch writer for "The Guardian" in 1993.
Split into simpler sentences: He joined "The Guardian" in 1968, later becoming the American correspondent for "The Observer" (and occasional guest commentator on National Public Radio's "Weekend Edition Saturday"). Simon then became the parliamentary sketch writer for "The Guardian" in 1993.