Where is the present day border between the United States and Mexico located?

The border between Texas and Mexico follows the course of the Rio Grande, or “Big River.”

West of Texas, the border is an artificial line drawn in the deserts of New Mexico, Arizona, and California.

To Spanish conquistadors, the border did not exist. They felt entitled to as much land as they could explore and settle. Probing north from the West Indies and Mexico, they laid claim to much of what is now the United States.

Had they kept it all, the official language in many parts of the country would today be Spanish.