It is considered a second line of defense.
The states that border Mexico are California, Arizona, New Mexico and Texas...
California borders Mexico.
Mexico cession
Nothing. California borders Mexico.
Zero. Mexico and California share a border.
Texas, California, New Mexico and Arizona all border Mexico.
California's southern border is shared with the country of Mexico.
Mexico
California was acquired from Mexico at the end of the Mexican-American War (1846-1848). Since then, southern California has been part of the US-Mexico Border.
At the California/Mexico border it is a matter of inches.
California, Arizona, New Mexico, and Texas border Mexico. Texas, Louisiana, Mississippi, Alabama, and Florida border the Gulf of Mexico.
750 mi