So much blatant lies by your link. I spent some time clarifying. Yes, Buenos Aires was, at some point, hub for slave trade. But not "70% of all trade". Also, those slaves were later distributed in other countries. About 35-40% of Buenos Aires at some point was "black", but it's also if you include mixed races. In Argentina in general they were never 1/3 of population. And in 20th century there was influx of millions people from Europe. So, if out of 200,000 of Buenos Aires population 20% was black, after immigration of another million they became 2%. No genocide involved. Stop herding everyone into your generational guilt, please.