The mexican-american war a. resulted in a large portion of territorial land going to mexico. b. resulted in the addition of territorial new mexico to the u. s. c. had no real impact on the history of the u. s. d. happened after the civil war.

its b

answer: 1

explanation:

im pretty sure

one of the main reasons was definitely slavery. back in 1861, republican abraham lincoln was elected and ended up being a major influence in the slavery business. slavery greatly affected the texas economy because back in 1845 during the annexation of texas, slaves became a big part of the texas population. many texans that were in favor of the secession influenced groups through party ties.