This
paper explains that Manifest Destiny, which began with the New York journalist, John Louis O'Sullivan, in 1845, was
held by the Democratic Republicans during the presidency of James Madison to provide a sense of mission to
citizens by using the phrase to promote and justify territorial expansion across the North American continent. The author points out that another desire of the politicians and leaders was the acquisition of new lands because land represented potential wealth, income, freedom, and self-sufficiency. The
paper stresses that, as the citizens of the United States spread westward, intense conflict developed with the Native Americans and with Mexicans in Texas; Manifest Destiny was one of the driving factors behind the Mexican-American War of 1846, which resulted in the loss of nearly half of Mexico's territory to the United States and the long-term destabilization of that country.