Library classification of a piece of work consists of two steps. Firstly, the subject or topic of the material is ascertained. Next, a call number (essentially a book's address) based on the classification system in use at the particular library will be assigned to the work using the notation of the system.
Library of Congress and the Snead system. The Thomas Jefferson Building of the Library of Congress was completed in 1897. This is where this type of book storage was first used. The engineer in charge of construction was Bernard Richardson Green. He made a number of alterations to the Gore Hall design, including the use of all-metal shelving.