Manifest Destiny was always a general notion rather than a specific policy. The term combined a belief in expansionism with other popular ideas of the era, including American exceptionalism, Romantic nationalism, and a belief in the natural superiority of what was then called the "Anglo-Saxon race". While many writers focus primarily upon American expansionism when discussing Manifest Destiny, others see in the term a broader expression of a belief in America's "mission" in the world, which has meant different things to different people over the years. This variety of possible meanings was summed up by Ernest Lee Tuveson, who wrote:
"A vast complex of ideas, policies, and actions is comprehended under the phrase 'Manifest Destiny'. They are not, as we should expect, all compatible, nor do they come from any one source.
The concept of Manifest Destiny has acquired a variety of meanings over the years, and its inherent ambiguity has been part of its power. In the generic political sense, however, it was usually used to refer to the idea that the American government was "destined" to establish uninterrupted political authority across the entire North American continent, from one ocean to the other.John L. O'Sullivan, sketched in 1874, was an influential columnist as a young man, but is now generally remembered only for his use of the phrase "Manifest Destiny" to advocate the annexation of Texas and Oregon.
Journalist John L. O'Sullivan, an influential advocate for the Democratic Party, wrote an article in 1839 which, while not using the term "Manifest Destiny", did predict a "divine destiny" for the United States based upon values such as equality, rights of conscience, and personal enfranchisement-- "to establish on earth the moral dignity and salvation of man". This destiny was not explicitly territorial, but O'Sullivan predicted that the United States would be one of a "Union of many Republics" sharing those values.
Six years later O'Sullivan wrote another essay which first used the phrase Manifest Destiny. In 1845 he published a piece entitled Annexation in the Democratic Review, in which he urged the United States to annex the Republic of Texas, not only because Texas desired this, but because it was "our manifest destiny to overspread the continent allotted by Providence for the free development of our yearly multiplying millions". Amid much controversy, Texas was annexed shortly thereafter, but O'Sullivan's first usage of the phrase "Manifest Destiny" attracted little attention.
O'Sullivan's second use of the phrase became extremely influential. On December 27, 1845 in his newspaper the New York Morning News, O'Sullivan addressed the ongoing boundary dispute with Great Britain in the Oregon Country. O'Sullivan argued that the United States had the right to claim "the whole of Oregon":
"And that claim is by the right of our manifest destiny to overspread and to possess the whole of the continent which Providence has given us for the development of the great experiment of liberty and federated self-government entrusted to us."
That is, O'Sullivan believed that God ("Providence") had given the United States a mission to spread republican democracy ("the great experiment of liberty") throughout North America. Because Britain would not use Oregon for the purposes of spreading democracy, thought O'Sullivan, British claims to the territory should be overruled. O'Sullivan believed that Manifest Destiny was a moral ideal (a "higher law") that superseded other considerations.
O'Sullivan's original conception of Manifest Destiny was not a call for territorial expansion by force. He believed that the expansion of the United States would happen without the direction of the U.S. government or the involvement of the military. After "Anglo-Saxons" emigrated to new regions, they would set up new democratic governments, and then seek admission to the United States, as Texas had done. In 1845, O'Sullivan predicted that California would follow this pattern next, and that Canada would eventually request annexation as well. He disapproved of the outbreak of the Mexican-American War in 1846, although he came to believe that the outcome would be beneficial to both countries.
Ironically, O'Sullivan's term became popular only after it was criticized by Whig opponents of the Polk administration. On January 3, 1846, Representative Robert Winthrop ridiculed the concept in Congress, saying "I suppose the right of a manifest destiny to spread will not be admitted to exist in any nation except the universal Yankee nation." Winthrop was the first in a long line of critics who suggested that advocates of Manifest Destiny were citing "Divine Providence" for justification of actions that were motivated by chauvinism and self-interest. Despite this criticism, expansionists embraced the phrase, which caught on so quickly that its origin was soon forgotten. O'Sullivan died in obscurity in 1895, just as his phrase was being revived. In 1927, a historian determined that the phrase had originated with him.