But not until late in August did he overcome the resistance of the combined opposition and gain the floor.

The watchmen were caught off guard when Sumner introduced an amendment to an appropriation bill which enabled him to deliver a carefully prepared address, several hours in length, calling for the repeal of the law.
The first part of this speech is devoted to the general topic of the relation of the national Government to slavery and was made in answer to the demand of Calhoun and his followers for the direct national recognition of slavery.

For such a demand Sumner found no warrant.

By the decision of Lord Mansfield, said he, "the state of slavery" was declared to be "of such a nature, that it is incapable of being introduced on any reasons, moral or political, but ONLY BY POSITIVE LAW....

it is so odious, that nothing can be suffered to support it but positive law." Adopting the same principle, the Supreme Court of the State of Mississippi, a tribunal of slaveholders, asserted that "slavery is condemned by reason and the Laws of Nature.