I don’t know about you, but my knowledge about Christopher Columbus is pretty rusty.  So, let’s start out with a quiz, which is usually pretty popular around here:
Columbus Day Trivia Quiz

I know that this holiday has become politically incorrect in some quarters in the USA, and in many Latin American countries, but I am not addressing those grievances here today, though you are free to talk about it, if it interests you.
For the serious among you, here is a program produced by the History Channel:

For the unserious, here is a more light-hearted take on the subject:
https://www.youtube.com/watch?v=s69cC5JgEls