New knowledge in old books

It’s funny how flat earth was taught in school Ruth up into the 1940’s.
When I was in grade school in the 1970’s. They taught us. That people during Columbus’s time thought the world was flat. But he set out to prove it wrong. Then he found the new world. I recall our books showed a drawing of a ocean that fell off into nothing. It was complete with sea monsters and Columbus’s ship. Wow! Memories 😄 And there wasn’t even a ice wall spoken of. 🤣
So just in my lifetime. They have changed history. And in my parents lifetimes they’ve really changed it.
Old books are very valuable. Lost knowledge. I would love to get my hands on some old history books.
Pray