How did slavery cause conflict between mexico and the united states

The Mexican-American war (1846-1848) changed the slavery debate. It almost doubled the size of the United States and began a debate, between Northerners and Southerners, over what to do with the newly acquired land.

Explanation:

c 3 branches because idk why they had 3 well when:

you think of it there are still contrys with 3

it made them more prductive and efficent but with the change of polcies less and les got into the navy