Anna's Archive is the biggest open library I've ever found. You can find and download pretty much any book ever published there. Recently, they hosted a competition to see who could best visualize all the published books using their ISBN numbers. This one by Phiresky won:

https://phiresky.github.io/blog/2025/visualizing-all-books-in-isbn-space/

Looking through these shelves feels like looking out of an airplane window or walking through a graveyard. Each book probably mattered a lot to somebody. I hope you get the same thing out of it that I did.