Heather Cox Richardson shares a brief history of the Chicano movement of the 1960s. She uses the 1970 police killing of journalist Rubén Salazar as a launch point.
… in the 1960s, young Mexican Americans, most of whom had been born in the U.S., began to reimagine their community and its position in the United States. Calling themselves “Chicanos,” they called for a new identity based in the understanding that they were not outsiders at all, but rather natives of the northern region of old Mexico, a region that did not become part of the United States until long after the Chicano people–Indigenous Americans mixed with the descendents of Spanish invaders–had settled there.
Chicanos noted that they had not moved into the United States, but rather the United States border had moved over them. The U.S. had taken over the land on which they lived in 1848 after the U.S.-Mexico War. The Treaty of Guadalupe Hidalgo, which had established the new boundary between the two countries far to the south of where it had been before, was supposed to guarantee the land titles of those Mexican landowners over whom the border had moved. But U.S. courts had disregarded the terms of the treaty and refused to recognize the rights of Mexicans, most of whom lost their land.
I knew that the US took the land I live on from Mexico in 1848. We learned about that in public school in New York, where I grew up. But until now I did not make the connection that many of my Latino neighbors have ancestry in America far longer than my own.