Read "Pastwatch, the Redemption of Christopher Columbus".
Speculative fiction set in a future where the end is near --- and the idea is to travel bask in time and change just one person to set the world on a better course ........ which they do. History about meso america, columbus,e tc. read it you'll like it, itmakes you think and you will learn something.
Then read - "1421, The Year the Chinese Discovered the World".
Columbus was not only a monster, he was 70 years late !