Dorchester used to be all Irish and the city next to it, Roxbury was all blacks. They used to take turns killing each other every weekend. One weekend some blacks would kill an Irish kid, the next weekend some Irish kids would kill a black kid.
Sounds like the populations of the two cities have mixed or become, more inclusive.
Dorchester guy here. This school is not in the Irish sector.
Busing in the 1970s caused rioting. Media blamed whites, said they were just racists.
When I grew up, I was in a CYO band (living in the comparative sticks about 30 miles West of Boston) that competed agains groups closer to Boston, such as Neponset, Jamaica Plain, et. One of the groups was from Dorchester, and they had a bad reputation for violence and thuggery, even way back then. I am sure it is far worse now.
Dorchester has been mixed for about 30-40 years I understand. Both Dorchester and Roxbury are within the city limits of Boston.
I go back a really long way and I would have said Dorchester was Roxbury redux. Course if you go far enough back everything was probably Irish at some point...