Who was the leader of the free-soil party and what was their slogan?

The main leaders were Salmon P. Chase and John P. Hale. I believe there slogan was the whig

The main party leaders were Salmon P. Chase of Ohio and John P. Hale of New Hampshire. The Free Soil candidates won 10% of the popular vote in 1848 but no electoral votes, in part because the nomination of Van Buren discouraged many anti-slavery Whigs from supporting them.