These questions are all directly related to the concept of "manifest destiny" as articulated by John O'Sullivan, a newspaper editor who authored several widely-read essays on American expansion in the 1830s and 1840s. In one essay entitled "The Great Nation of Futurity," O'Sullivan claimed that the United States was different from any nation in history, and its very existence represented a rejection of the old, corrupt European monarchies that had waged dynastic wars for centuries. "America," he wrote, "is destined for better things." He believed that the United States was divinely chosen to lead the world, as a nation of "progress, of individual freedom, of universal enfranchisement."
In practice, O'Sullivan and others who argued for manifest destiny believed that the United States, because it was supposedly different than other nations, had the right, or even the duty, to expand westward to the Pacific Ocean. Thus O'Sullivan argued vigorously for the annexation of Texas and California on the grounds that the Mexican government was supposedly unable to bring civilization to the region. "The Anglo-Saxon foot," he wrote of California, "is already on its borders." As this quote demonstrates, the ideology of manifest destiny was highly racialized, and its promoters, like many in the nineteenth century, tended to conflate race and culture. The spread of culture, civilization, and democracy advocated by Sullivan was only compatible, in the minds of most, with white "Anglo-Saxon" men. But significantly, he and others believed that they had been chosen by God and that the spread of American culture was inevitable, the "destiny" of an exceptional people.