Melvil Dewey developed the Dewey Decimal Classification (DDC) system as a way to organize and classify the books in the Amherst College Library, where he was working as a librarian in the late 19th century. At the time, library classification systems were generally based on a hierarchical structure, with broad main classes at the top and more specific subclasses and categories below them. However, Dewey felt that these systems were too broad and general, and he believed that there was a need for a more detailed and specific classification system that would allow for greater precision and accuracy in organizing and accessing library materials.
To develop his own classification system, Dewey began by studying the existing systems that were in use at the time, and he drew on his own knowledge and experience as a librarian to identify the strengths and weaknesses of each system. He then used this information to create a new classification system that was based on a decimal numbering system, with 10 main classes at the top and more specific categories and subcategories below them.
Dewey’s classification system was designed to be flexible and adaptable, and he believed that it would be more efficient and effective than the existing systems for organizing and accessing library materials. He published the first edition of the DDC system in 1876, and it has since become one of the most widely used library classification systems in the world.