I am talking about equating present-day conditions for black people, which aren't what they should be but aren't anything like Nazi Germany, with an intense focused campaign of genocide.

That's what you do when you are simply comparing years.

In fact, you're making the same grotesque mistake when you lump everything together into "535 years". The first 30-odd years of your reckoning didn't even have any black people in the Americas. The last country in the Americas to outlaw slavery was Brazil in 1888, which means the last 134 years have been substantially different than the previous howevermany you want to count. If you're talking about Europeans taking slaves anywhere, 1492 doesn't have anything to do with that at all (they started earlier than that!).

It's incredibly disrespectful to people who suffered and died as part of the slave trade to blithely glom that on to modern problems.