Mexico signed a treaty to end war with America and this land was given to the United States.
This can be attributed to industrialization. Industrialization helped fuel the start of imperialism in the 19th century. ... In order to maximize the countries profits, these industrialized nations went out to find nations that they could exploit natural resources and cheap labor from thus leading to imperialism
Hope my answer helps uh ✌️
They had a lot of help from allies and a lot of troops
land routes were closed off by Ottoman Turks