[magpi3]

Of course. Nation states have not been round that long. Just a few hundred years.

Jewish culture exists throughout the world. All religious cultures actually. Islamic culture.

Immigrants often retain many aspects of their culture when they move to a new country.

The US itself is a huge mismash of different cultures. People in the US are not bound by a single cultural identity. They are bound by the constitution and the principles and values it represents.