The correct answer to this open question is the following.
Polk's state of the union address, although celebratory, was a precursor to the Manifested Destiny and the advocacy of annexation.
US President James Knox Polk delivered his state of the union address on December 2, 1845. A considerable number of lines were dedicated to the Mexican-American conflicts and the idea that the United States had the right to own the majority of the North American territory.