Millions of people in the United States today identify themselves as Mexican immigrants or Mexican Americans, and are among both the oldest and newest inhabitants of the nation. Some Mexicans were already living in the Southern and Western regions of the North American continent centuries before the United States existed. Many more Mexicans came to the country during the 20th century, and Mexican immigrants continued to arrive in the late 20th and early 21st centuries.
The multicultural inheritance of Mexican Americans is rich and complex. It reflects the influences of Spain, Mexico, and indigenous cultures, and has been shaped by hundreds of years of survival and adaptation in the crucible of North American history. This history was also shaped by wars and depressions, by the Treaty of Guadalupe Hidalgo and the Gadsden Purchase, and by shifting attitudes toward immigration.
Mexican immigration occupies a complex position in the U.S. legal system and in U.S. public opinion. Immigration law has swung back and forth throughout the 20th century, at times welcoming Mexican immigrants and at other times slamming the door shut on them. The public reception of this immigrant group has also been unpredictable; Mexican immigrants have been able to make a place for themselves in communities across the United States, but frequently have had to battle hostile elements in those same communities to survive.
Mexican immigrants and their descendants now make up a significant portion of the U.S. population and have become one of the most influential social and cultural groups in the country. Mexican American culture will likely continue to shape U.S. life in language, politics, food, and daily living and will help define the nation's identity for a new century.