How does the United State's desire to acquire land from Mexico support their belief in Manifest Destiny

Question- How does the United State's desire to acquire land from Mexico support their belief in Manifest Destiny

Answer- Americans believed that they had a right to any land they wanted. First used in 1845, the term Manifest Destiny conveyed the idea that the rightful destiny of the US included imperialistic expansion. The idea of Manifest Destiny is as old as America itself. By the time Texas was admitted to the Union as a state in December 1845, the idea that the United States must inevitably expand westward all the way to the Pacific Ocean had taken firm hold among people from different regions, classes and political persuasions.  The phrase “Manifest Destiny,” which emerged as the best-known expression of this mindset, first appeared in an editorial published in the July-August 1845 issue of The Democratic Review.  In it, the writer criticized the opposition that still lingered against the annexation of Texas, urging national unity on behalf of “the fulfillment of our manifest destiny to overspread the continent allotted by Providence for the free development of our yearly multiplying millions.”  As the phrase also appeared in a nearly identical context in a July 1845 article in the New York Morning News, its originator is believed to be John O’Sullivan, the editor of both the Democratic Review and the Morning News at the time. That December, another Morning News article mentioned “manifest destiny” in reference to the Oregon Territory, another new frontier over which the United States was eager to assert its dominion.