I grew up in suburban Chicago. Northerners paint themselves as open-minded saints as far as race relations are concerned, but I know from personal observation that there are just as many bigots up there as in the South. But the winner writes the history forever, so Southerners are all ignorant hillbillies.
Gangs of New York presents some of that.
A look at Chicago history would be interesting for the self-righteous Yankees.
The summer of 1919 should be noted, as well as the anti-Black demonstrations by Whites through the 40’s and 50s. Race riots were an annual event in 1966-1968. Even as recently as 1977 Chicago wasn’t exactly a haven of love between the races.