How did the Mexican-American War ignite a conflict over slavery between the North and the South?

Answer 1

Read this page and the next, 30d.

http://www.ushistory.org/us/30c.asp

Answer 2

And I'm sure you know from your text materials what the result of the Mexican-American War was: the addition of vast new territories to the U.S.

Answer 3

This is very late but the answer is the north wanted the new land gained to be slave free land and the south wanted it to be slave lands.