自由土地党
The election of 1848 produced a new President from the Whig Party, Zachary Taylor. President Polk did not seek reelection because he gained all his objectives in his first term and because his health was declining. From the election emerged the Free Soil Party, a group of anti-slavery Democrats who supported Wilmot's Proviso. The creation of the Free Soil Party foreshadowed the collapse of the Second party system; the existing parties could not contain the debate over slavery for much longer.