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.
The American librarian and reformer Melvil Dewey established the Dewey decimal system of classifying books and played a prominent role in developing professional institutions for librarians .
Melvil Dewey was born in Adams centre, New York, on December 10, 1851, the youngest of five children of impoverished parents. His father, a boot maker and keeper of a general store and his sternly religious mother inculcated principles of hard work and economy in the youth along with a sense of self righteousness that marked him throughout his life. He early demonstrated strong mathematical ability and a fascination with systems and classifications. His education was slowed by the need to earn money, and he did not enter Amherst College until he was 19, at Amherst College he belonged to Delta Kappa Epsilon, earning a bachelor's degree in 1874 and a master's in 1877. While still a student, he founded the Library Bureau which sold high quality index cards and filing cabinets, and established the standard dimensions for catalog cards.
As a young adult he advocated spelling reform; he changed his name from the usual "Melville" to "Melvil", without redundant letters, and for a time changed his surname to "Dui".
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. In 1895 Dewey founded the Lake Placid Club with his wife Annie. He and his son Godfrey had been active in arranging the Winter Olympics which took place at Lake Placid—he was chairman of the New York State Winter Olympics Committee. In 1926 he went to Florida to establish a new branch of the Lake Placid Club.