The United States is sometimes referred to as a "nation of immigrants." You may have also heard the phrases "salad bowl" and "melting pot." In its short history the United States has seen many waves of immigrants come to its shores and borders.
Fleeing political or religious persecution or searching for better economic conditions, many people have left their native lands to live in America. This has resulted in a very diverse U.S. population. People living here have different heritages, religious beliefs, ethnicity, languages, and national origins. Though there are these differences, Americans are bound together by basic political values and principles described in historical documents.
However, living in the United States does not automatically make one an American citizen. Residents of the United States can be aliens, nationals, or citizens. Aliens are people who have emigrated from a foreign country. They have some of the same freedoms and legal rights as U.S. citizens, but they cannot vote in elections. American nationals are natives of American territorial possessions. They have all the legal protections which citizens have, but they do not have the full political rights of U.S. citizens. Persons born in the U.S. or born to U.S. citizens in foreign countries, are automatically citizens of the United States. Persons born in other countries who want to become citizens must apply for and pass a citizenship test. Those who become citizens in this manner are naturalized citizens.
All American citizens enjoy the freedoms, protections, and legal rights which the Constitution promises.