There was lots of pre-columbian contact. In fact Columbus himself only got into the idea of the route by being on a boat with a sailor who had been on a boat blown off course and ended up in the likely caribbean and told Columbus he had been to India. There were many similar stories at the time and Columbus actually collected them from people who had been or heard the stories and used them to formulate his initial route.
The source is a really great well researched book about Columbus and all the insane things that he did. Most of what you here about him is extremely light on details and facts, he was definitely like an Albert Einstein of navigation. He knew enough even after being shipwrecked and stranded for a month to accurately determine exactly where he was in the world and the timing of an eclipse down to the hour which he used to convince the indigenous population that God was mad at them for not feeding him!
https://www.amazon.com/Columbus-Voyages-1492-1504-Laurence-Bergreen/dp/014312210X
> Wasn't it more like mass murder and rape?
Not really no, in fact his primary ambition was to bring more subjects to the queen and converting them to Christianity. Even saying cool with slavery is somewhat of an overstatement as slavery in the way we see it wasn't established until a bit later. At that time Europe was still in feudalism and Columbus say himself as a subject of the queen in the same way he would see others as potentially being his subjects or the subjects of others. There was certainly some overlap into modern slavery with some caribs being taken to Europe to be sold. And he did other bad stuff too, no doubt.
BUUUUT that's not the point. None of that shit is what made him a standout. There were 1000s of people being brutal and rape'n and rob'n (that's basically what Knights did) all over Europe and where ever they could go.
Columbus is special because of the crazy navigation stuff he did. Like staying up 30+ days until he nearly died and suffered from blindness while they were stuck in the doldrums. Then giving seemingly random instructions when he woke up and was still confined to a bed that got them out of it. Or when a storm blew them hopelessly of course and he stayed in his room for 2 days while everyone freaked out then he came out, gave some directions and said told them where they would be in 3 days and went back in his room and didn't come out until they were there.
If you actually have any real interest this is a great book.
https://www.amazon.com/Columbus-Voyages-1492-1504-Laurence-Bergreen/dp/014312210X
I reckon it was from this book:
https://www.amazon.com/Columbus-Voyages-1492-1504-Laurence-Bergreen/dp/014312210X