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This term originated about the time of the acquisition of additional territory from Mexico in 1848. A suggestion was made of a middle course between the Wilmot Proviso, which prohibited the introduction of slavery into newly acquired or organized territories, and the positive permission of slavery under federal legislative enactment ; namely, the question was to be settled by the inhabitants of the territories. The Kansas-Nebraska bill of 1854 purported to enforce the popular sovereignty idea. The Dred Scott decision of 1857 decided against it. The Democratic National Convention of 1856 approved of non-interference by Congress with slavery in the Territories. Douglas, of Illinois, was an ardent advocate of this policy, and he vainly defended it against the Dred Scott decision. The popular sovereignty idea disappeared with the outbreak of the rebellion. It was called in derision "squatter sovereignty."