many black people in America do have a shared cultural heritage, and black culture is a thing that actually exists (which white people have a habit of stealing and profiting off of, but that's another argument for another day). white Americans tend to be more culturally diverse because of the influx of immigration in the 18/1900s. back then, the different cultures didn't want to mingle (or were prevented from mingling), so up until recent years (and even currently) there were Irish neighborhoods which were separate from the Italians, Poles, etc. sure, there have been black immigrants, too, and from various places, but the greater part of the Black population are not recent immigrants, they are the descendants of slaves and freedmen, and they have established a shared culture.