Humanities › History & Culture Manifest Destiny: What It Meant for American Expansion What the Term Meant and How It Impacted 19th Century America Share Flipboard Email Print Getty Images History & Culture American History America Moves Westward Basics Important Historical Figures Key Events U.S. Presidents Native American History American Revolution The Gilded Age Crimes & Disasters The Most Important Inventions of the Industrial Revolution African American History African History Ancient History and Culture Asian History European History Genealogy Inventions Latin American History Medieval & Renaissance History Military History The 20th Century Women's History View More By Robert McNamara History Expert Robert J. McNamara is a history expert and former magazine journalist. He was Amazon.com's first-ever history editor and has bylines in New York, the Chicago Tribune, and other national outlets. our editorial process Robert McNamara Updated June 01, 2019 Manifest Destiny was a term that came to describe a widespread belief in the middle of the 19th century that the United States had a special mission to expand westward. The specific phrase was originally used in print by a journalist, John L. O'Sullivan, when writing about the proposed annexation of Texas. O'Sullivan, writing in the Democratic Review newspaper in July 1845, asserted "our manifest destiny to overspread the continent allotted by Providence for the free development of our yearly multiplying millions." He was essentially saying the United States possessed a right granted by God to take territory in the West and install its values and system of government. That concept was not especially new, as Americans had already been exploring and settling westward, first across the Appalachian Mountains in the late 1700s, and then, in the early 1800s, beyond the Mississippi River. But by presenting the concept of westward expansion as something of a religious mission, the idea of manifest destiny struck a chord. Though the phrase manifest destiny may seem to have captured the public mood of the mid-19th century, it was not viewed with universal approval. Some at the time thought it was simply putting pseudo-religious polish on blatant avarice and conquest. Writing in the late 19th century, future president Theodore Roosevelt, referred to the concept of taking property in furtherance of manifest destiny as having been "belligerent, or more properly speaking, piratical." The Push Westward The idea of expanding into the West had always been attractive, since settlers including Daniel Boone moved inland, across the Appalachians, in the 1700s. Boone had been instrumental in the establishment of what became known as the Wilderness Road, which led through the Cumberland Gap into the lands of Kentucky. And American politicians in the early 19th century, such as Henry Clay of Kentucky, eloquently made the case that the future of America lay westward. A severe financial crisis in 1837 emphasized the notion that the United States needed to expand its economy. And political figures such as Senator Thomas H. Benton of Missouri, made the case that settling along the Pacific would greatly enable trade with India and China. The Polk Administration The president most associated with the concept of manifest destiny is James K. Polk, whose single term in the White House was focused on the acquisition of California and Texas. It's worth nothing that Polk had been nominated by the Democratic Party, which was generally closely associated with expansionist ideas in the decades before the Civil War. And a Polk campaign slogan in the 1844 campaign, "Fifty-four forty or fight," was a specific reference to expanding into the Northwest. What was meant by the slogan was that the border between the United States and British territory to the north would be at north latitude 54 degrees and 40 minutes. Polk got the votes of the expansionists by threatening to go to war with Britain to acquire territory. But after he was elected he negotiated the border at 49 degrees north latitude. Polk thus secured the territory that today is the states of Washington, Oregon, Idaho, and parts of Wyoming and Montana. The American desire to expand into the Southwest was also satisfied during Polk's term in office as the Mexican War resulted in the United States acquiring Texas and California. By pursuing a policy of manifest destiny, Polk could be considered the most successful president of the seven men who struggled in the office in the two decades before the Civil War. In that period between 1840 and 1860, when most occupants of the White House couldn't point to any real achievements, Polk had managed to greatly increase the territory of the nation. Controversy of Manifest Destiny Though no serious opposition to westward expansion developed, the policies of Polk and the expansionists were criticized in some quarters. Abraham Lincoln, for instance, while serving as a one-term Congressman in the late 1840s, was opposed to the Mexican War, which he believed was a pretext for expansion. And in the decades following the acquisition of western territory, the concept of manifest destiny has been continually analyzed and debated. In modern times, the concept has often been viewed in terms of what it meant to the native populations of the American West, which were, of course, displaced or even eliminated by expansionist policies of the United States government. The lofty tone which John L. O'Sullivan intended when he used the term has not carried into the modern era.