How did industry bring an end to isolation?

it required more immigrants to work
it led to the need for more resources
it had to have a larger market
it used more machinery from around the world

How did most southern politicians of the 1860s feel about the issue of slavery? a) they supported slavery in current states, but were against its expansion into new states. b) they wanted to preserve slavery and supported its spread into new states. c) they wanted to prohibit the spread of slavery into new states and territories. d) they supported the emancipation of enslaved people in all states and new territories.