Answer:
The changing relationships among ethnic and racial groups in the United States have had a significant impact on national identity. As different groups of people have come together, the country has become more diverse, and this has led to a more complex understanding of what it means to be an American. This diversity has allowed for a greater appreciation of different cultures and perspectives, which has helped to create a more unified national identity. At the same time, the changing relationships between different ethnic and racial groups have also created tension and conflict, which has challenged the notion of a unified national identity.