In congress, the most infantile republicans were U.S. senator Charles Summer and the U.S. representative Thaddeus Stevens. they led the call for a war that would end slavery.
The answer for this question is: New England
The region of new England was the main target destination for the people who want to seek job opportunity during that time (mostly from Massachusetts)
Not only that, the economic growth in this region also give the people with enough resources to sustain their living so their mortality rate is really low.
