The Americans gained independence after the American revolution and this revolution helped them to get an identity that they belong to one nation.
Step-by-step explanation:
The people who were living in the United States of America were a colony of the Great Britain and they wanted to get freedom for that. For getting independence, the people fought a revolution which was known as the American revolution against the people of the Great Britain. This atmosphere which was created had new ideas, new sense of freedom developed the feeling of national identity.