What do you mean by this?
Half of the US would be part of Mexico, Texas was the first Mexican territory to become part of the US so the rest weren't hard to get since Texas was so big. I personally wish Texas would've stayed because if it would've, Mexico, my country, would be as powerful as the US.
BUT NAHHHHHHHHHHHH
It is a free market system. There are things such as private property rights, economic freedom and voluntary exchanges.