I was writing a memo just now, I wrote an unique and I just stopped and looked at it and realized it was wrong. My whole world had been turned upside down. Then I found this explanation and all is right with the world.
Liberty Party (1840) wanted to abolish slavery; Free Soil Party (1848) wanted to keep slavery from expanding into Western territories; American Party (Know-Nothings in 1854 & 1856) wanted to reduce immigration (nativism); Constitutional Union Party (1860) wanted a compromise between the North & South.
The modern Democratic Party is a direct descendant from this Democratic Party of 1824. The modern Republican Party is also a descendant of this factionalization of the old D-R Party. In the 1850s, the Whig Party was split over the issue of slavery - in effect a very public North/South split inside the Party.