The answer is Salad Bowl.
Salad bowl is a model of racial integration where people of different cultures live in harmony like the ingredients of a salad. Different American cultures are brought together, but they do not form together into a single homogeneous culture.
This term indicates that different ethnic groups are able to preserve their original cultures even if they assimilate well into their new host societies. The salad bowl approach can be compared to the idea of multiculturalism in Europe which means a partial integration only.
The traditional American melting pot conveyed the idea that, with time, generations of immigrants melt together. They abandon their cultures to become totally assimilated into the American society.
Salad bowl has become a more politically correct term, as it implies a society of many individuals with various ethnic and cultural identities living together in harmony.