I reckon if you could get there 10 years early you could probably prevent the entire thing. If you were capable of convincing some of the larger groups within the americas of the impending invasion, there were certainly people and resources enough to put together a small navy and start patrolling the eastern coast. Throw is some modern knowledge of firearms and metallurgy to help them develop some cannon, and Columbus never makes it to America.
Back in Europe people assume him lost at sea, and leave the atlantic untouched for another generation. With that much time to prepare, who knows how things play out.
The Constant, by Mark Chrysler.
Headlined as “a history of getting things wrong”, the host goes into deep dives about what we thought we knew, how we eventually came to figure out we were wrong, the repercussions of both.
It takes a seriously funny and well researched approach to a number of major events in our history, and I absolutely must recommend “the foolkiller” a five episode exploration of a submarine found at the bottom of the Chicago River then lost to history, with a very juicy footnote delivered several episodes later, that I dare not spoil for you.