Complex sentence: From 1883 to 1888 he was chief librarian at Columbia University, from 1888 to 1906 director of the New York State Library, and from 1888 to 1900 secretary and executive officer of the University of the State of New York.
Split into simpler sentences: From 1883 to 1888 he was chief librarian at Columbia University. From 1888 to 1900 Dewey served as secretary and executive officer of the University of the State of New York.