The modern Republican Party has a large contingent of rebadged Dixiecrats. As for Iowa, there had never been slavery in what we think of as the Midwest--north

The modern Republican Party has a large contingent of rebadged Dixiecrats. As for Iowa, there had never been slavery in what we think of as the Midwest--north of the Ohio River and of Missouri. However, the Dred Scott decision put it into question whether the states could maintain that status. I imagine that to have been a motivator for Midwesterners who did not wish to compete with slave labor.