In 1848, slavery and sectionalism began taking their toll on the country’s party system. The Whig Party was an early casualty. By 1860, national parties — those that contended for votes in both North and South — had been replaced by regional parties.

READING THE MAP How many slave states and how many free states does the map show? Estimate the percentage of new territory likely to be settled by slaveholders.

CONNECTIONS Who would be more likely to support changes in government legislation to discontinue the Missouri Compromise — slaveholders or free-soil advocates? Why?