Yes, the Irish did assimilate in America
There are still actual Italian-American and Jewish-American neighborhoods in America. Not to mention Polish-American neighborhoods.
Irish-American neighborhoods haven’t been an actual thing in large numbers since the 1980s.
South Boston, of Departed and Good Will Hunting fame, is now mostly recent college grads from the suburbs working in Boston
There are still actual Italian-American and Jewish-American neighborhoods in America. Not to mention Polish-American neighborhoods.
Irish-American neighborhoods haven’t been an actual thing in large numbers since the 1980s.
South Boston, of Departed and Good Will Hunting fame, is now mostly recent college grads from the suburbs working in Boston