American librarian Melvil Dewey was born in Adams Center, N.Y., on Dec. 10, 1851.  Dewey invented the Dewey Decimal System of Classification.  First implemented in 1876 in small libraries, the Dewey Decimal System is now used in most local and school libraries to catalogue books. Using general categories and short call-numbers, the system's 10 classes of subdivided subjects simplify the organization of libraries.