In the early 1850s, enforcement of the gave large numbers of northerners an eyewitness view of the heartlessness of slavery.

i believe the answer is a

do you have a list of sources to choose from?

hey, did you get this? could you me out?

they had many gains 1 one freedom for slaves the major cause of the civil war is that the   north wanted freedom for slaves but the south didn; t creaitng the civil war

another gain they have is poltiical influence

poltiical influence is a big thing everywhere even now peoplle are always trying to get the head up in poltics thats what they did by giving the republicians a good name for freeing slaves