Complex sentence: Clement Clarke Moore's wife, Catharine Elizabeth Taylor, was of English and Dutch descent being a direct descendant of the Van Cortlandt family, once the major landholders in the lower Hudson Valley of New York.
Split into simpler sentences: Clement Clarke Moore's wife, Catharine Elizabeth Taylor, was of English and Dutch descent. She was a direct descendant of the Van Cortlandt family, once the major landholders in the lower Hudson Valley of New York.