Northern lawmakers were hesitant to go to war with mexico because they feared
a. the southern land gained from mexico would end up as slave states.
b. the strength of the mexican army.
c. the southern land gained from mexico would end up as free states.
d. that spain would reconquer a weakened mexico.

A

some abolitionist lawmakers in north were afraid of the fact that slavery was main cause of the war (contrary to common belief that was it's main reason not the independence of texas, contrary the causes of civil war were far more complex) there was hesitation for going to war with mexico in both north and south (most prominent oppositionist was adams) 

D.successful because there were no legal protections for unions.