But in the case of Africans I'm positive there were a lot in the 1800s so that's why I'm still rather obsessed about the isssue.
Many died remaining in the south of the city during the yellow fever and cholera outbreaks of the 1870's, many black males were sent north to fight in the Guerra de la Triple Alianza and thus the remaining females tended to mix with the criollo population (they say a significant number of portenos have some African blood). Of the few that returned from the war many preferred to stay in Uruguay where there was still a large community of African descent.