The united stated has a trade agreement with canada and mexico called:

NAFTA :) is your answer, North American Free Trade Agreement is the long way of saying it.

location is the answer to this

from my own personal expirence food stamps has alot this makes it eaiser so we can affod bills and so we can life a better lifestyle not needing to worry about paying actual money to buy food since most people spend 100-300 dollars a month on food so this alot so we can afford other bills and other stuff we need