The Free Soil Party was a political party that sprang up in the 1840s in response to the national debate over slavery. The party did not last very long, but had a lasting impact because many of its leading men became the founders of the Republican Party.
Before the Free Soil Party arose, there were two parties, the Democrats and the Whigs. Both parties had wings that were pro-slavery and wings that were anti-slavery. As tensions over slavery grew, some of these Democrats and Whigs decided to split off and join a party that was anti-slavery.
The Free Soil Party was, however, not an abolitionist party. It did not call for the abolition of slavery where it existed. Instead, it argued that slavery should not be extended into territories where it did not already exist.