Don't beat me if this is ASB, but I've had this idea for a while, so I might as well post it for scrutiny.
What if rather than absorbing the Mexican cession area into the Union, the American Southwest became a region of American republics (IE, the Republic of Texas, Republic of California, Deseret) independent of but friendly to the United States government?
What if rather than absorbing the Mexican cession area into the Union, the American Southwest became a region of American republics (IE, the Republic of Texas, Republic of California, Deseret) independent of but friendly to the United States government?