Melville Louis Kossuth (Melvil) Dewey (December 10, 1851 – December 26, 1931) was an American librarian and educator, inventor of the Dewey Decimal system of library classification, and a founder of the Lake Placid Club.
Immediately after receiving his undergraduate degree he was hired to manage Amherst's library and reclassify its collections. Dewey worked out a new scheme that superimposed a system of decimal numbers on a structure of knowledge first outlined by Sir Francis Bacon.
Dewey copyrighted the system in 1876. This system has proved to be enormously influential; though many American libraries have since adopted the classification scheme of the Library of Congress, Dewey's system remains in widespread use.