Provience
Kill!
Would it not be easier to liberate Mexico like the US does to many other countries and slowly turn it into an extension of the US. Think of all the new voters and work force the government would have at their disposal. I get not wanting to absorb Canada but Mexico has some prime land worth taking. I have friends who are always going to Baja and they come back and tell me how they were hanging out on the beaches with all the hall of fame racers who retired and live there like kings.
name a place in the last 150 years that the US has "liberated and made an extension" of