[...] that all efforts by abolitionists or others, made to induce congress to interfere with questions of slavery, or to take incipient steps in relation thereto, are calculated to lead to the most alarming and dangerous consequences, and that all such efforts have an inevitable tendency to diminish the happiness of the people, and endanger the stability and permanency of the union, and ought not to be countenanced by any friend to our political institutions.
That language was contained in the platform for a particular political party between the years 1840 and 1856. Do you even need to guess which one?