A guy named Dewey, Melvil Dewey, did all the above.
The ALA was founded in 1876; the first library school opened in 1887 at Columbia University; and Dewey came up with his system for organizing and shelving non-fiction books in 1876.
(Fiction is shelved by the author of the book – EXCEPT folk tales, fairy tales, riddles which are in 398, and poetry and plays in 811-12.)
Non-fiction goes by the numbers – decimal numbers – EXCEPT biographies which are under 921 by the last name of the subject (Some libraries still shelve them according to what the subject is famous for, which seems a bit awkward. What if the person was famous in sports and music, both?).
Before Dewey invented his numbering system, some libraries arranged books to “look nice” by size; some put them alphabetically by title; some just had a fixed spot on a shelf. When a new book came in, everything had to be rearranged.
Ask your bffl (best friend forever librarian) for all ten Dewey categories and all the hundreds of sub-categories. Here are three: 200 is religion, 300 is social studies, 600 is applied science (science you use).
So, for example, the Dewey number for a book on the commercial processing of kidney beans is 664.805652. I know you are rushing to get that book even as we speak – unless you agree with the friend who said, “Like I care about kidney beans.”
If you are researching at an academic library such as Harvard or Yale, say, you will probably NOT use the Dewey Decimal System. Instead, you’ll use the Library of Congress Classification System which is more, well, academic.
One last fact on Dewey. He was born Melville Louis Kossuth Dewey, He changed this to Melvil Dewey, and even considered changing Dewey to Dui, the better to get rid of extra letters.
Oh, one more last fact. When did he figure out how to organize books? He wrote, “one Sunday during a long sermon … without hearing a word, my mind absorbed in the problem, the solution flashed over me.”