It's mainly because of A and B, because after the war, the industrial resolution happened, and farmers are replaced by machines, farmers has no work to do, their speed is no compare to the machines, so they must move to another place. Also the population in Europe is growing in a extremely fast speed. Hope that helps :)
Answer:
hated by roman republicans
A. The US made the Gadsden Purchase.
The US never sold Texas. US won the war. Mexican cession was the US taking land.
I think D if I’m wrong I’m so sorry
