During the years surrounding James K. Polk's presidency, the United States of America grew economically, socially, and most noticeably geographically. In this time period, the western boundaries of the Untied States would be expanded all the way to the Pacific Ocean. Many Americans in the 19th century believed that the acquisition of this territory to the west was their right and embraced the concept of "Manifest Destiny". This concept was the belief that America should stretch from sea to shining sea and it was all but inevitable. Under the cover of "Manifest Destiny", President Polk imposed his views of an aggressive imperialistic nation. Imperialism is the practice of extending the power and dominion of a nation by direct territorial acquisitions over others, and clearly America took much of this land by force rather than peaceful negotiations with other nations. Polk acquired three huge areas of land to include: the Republic of Texas, the Oregon Territory, and the states of California, Nevada, Utah, Arizona, and New Mexico under the Mexican Cession.
Just before Polk's presidency Texas had freed itself from Mexican rule and desired American annexation. This desire came from thousands of former American citizens that settled in Texas in the 1820s. This was due to the Mexican government supplying huge land grants to entice new settlers to Texas and secure its northern border from America. The Mexican government failed to realize the true impact that their persuasion of Americans for settlement would cause. In 1830, Mexico finally put a freeze on all American immigration due to the large number of American settlers and their certain revolution. In 1836, The Republic of Texas was established when General Santa Anna was forced to sign a treaty recognizing the independence of Texas. Southern slave owners quickly took interest in this land due to its rich soil that was great for cotton and settled there by the