Complex sentence: William Backhouse Astor Sr. (September 19th 1792-November 24th 1875) succeeded his father John Jacob Astor as the wealthiest man in America, though he was the last member of the Astor family to enjoy this distinction.
Split into simpler sentences: William Backhouse Astor Sr. (September 19,1792-November 24,1875) was, on inheriting the wealth of his father John Jacob Astor, the wealthiest man in America. He was the last member of the Astor family to enjoy this distinction.