In 1845 James K. Polk was elected the new President of the United States. He ran on a Democratic platform supporting the annexation of Texas and western expansion (PBS 1). It would not be long before he took action. The action came against Mexico and the purposes for it were more than likely manufactured ("The Mexican War" 1). While it has been suggested that the rallying cause that led to the Mexican-American War was to promote western expansion, or Manifest Destiny, as it was called at the time, the war was played against a backdrop of slavery versus anti-slavery (Heys 1). The thesis of this paper will be to show that James K. Polk manufactured the need for a Mexican-American war in order to promote western expansion.

To support this thesis it is necessary to give a brief background of events leading up to the war between Mexico and the United States...