James Polk’s massive hate boner for Mexico after Mexico lost the Mexican-American war (which was incensed over territorial disputes over Texas before the Civil War funnily enough) and also the USA’s version of Lebensraum, Manifest Destiny.
California didnt really have a large enough Mexican population compared to the Southern parts of Mexico to defend from the USA, the population boom didnt come until much later
James Polk’s massive hate boner for Mexico after Mexico lost the Mexican-American war (which was incensed over territorial disputes over Texas before the Civil War funnily enough) and also the USA’s version of Lebensraum, Manifest Destiny.
California didnt really have a large enough Mexican population compared to the Southern parts of Mexico to defend from the USA, the population boom didnt come until much later