Originally developed by Herbert Putnam in 1897. It was influenced by Cutter Expansive Classification and DDC, designed for the use by the Library of Congress. It has been criticized as lacking a sound theoretical basis; many of the classification decisions were driven by the particular practical needs of that library, rather than considerations of rationality. In particular, the classification often shows bias towards the United States and towards Christianity.
Although it divides subjects into broad categories, it is essentially enumerative in nature.
See Library of Congress catalogue scheme for an attempt to organize Wikipedia according to that scheme.