Well, one cause they had is coal. they used that for railroads and factories. but coal caused a lot of damage to the environment at that time. hopefully this is correct. good luck.
Mexico wouldn't negotiate.
Manifest Destiny.
Pacific Port.
There is many more but these are the ones I remember
I think it’s C
Sorry if I am wrong
Answer: A. unions, Congres
Explanation:
hope it help if not then sorry
