<P> The controversy was eventually ended by the Mexican Cession, which added the territories of Alta California and Nuevo México to the United States, both more sparsely populated than the rest of Mexico . Like the All Oregon movement, the All Mexico movement quickly abated . </P> <P> Historian Frederick Merk, in Manifest Destiny and Mission in American History: A Reinterpretation (1963), argued that the failure of the "All Oregon" and "All Mexico" movements indicates that manifest destiny had not been as popular as historians have traditionally portrayed it to have been . Merk wrote that, while belief in the beneficent mission of democracy was central to American history, aggressive "continentalism" were aberrations supported by only a minority of Americans, all of them Democrats . Some Democrats were also opposed; the Democrats of Louisiana opposed annexation of Mexico, while those in Mississippi supported it . </P> <P> After the Mexican--American War ended in 1848, disagreements over the expansion of slavery made further annexation by conquest too divisive to be official government policy . Some, such as John Quitman, governor of Mississippi, offered what public support they could offer . In one memorable case, Quitman simply explained that the state of Mississippi had "lost" its state arsenal, which began showing up in the hands of filibusters . Yet these isolated cases only solidified opposition in the North as many Northerners were increasingly opposed to what they believed to be efforts by Southern slave owners--and their friends in the North--to expand slavery through filibustering . Sarah P. Remond on January 24, 1859, delivered an impassioned speech at Warrington, England, that the connection between filibustering and slave power was clear proof of "the mass of corruption that underlay the whole system of American government". The Wilmot Proviso and the continued "Slave Power" narratives thereafter, indicated the degree to which manifest destiny had become part of the sectional controversy . </P> <P> Without official government support the most radical advocates of manifest destiny increasingly turned to military filibustering . Originally filibuster had come from the Dutch vrijbuiter and referred to buccaneers in the West Indies that preyed on Spanish commerce . While there had been some filibustering expeditions into Canada in the late 1830s, it was only by mid-century did filibuster become a definitive term . By then, declared the New - York Daily Times "the fever of Fillibusterism is on our country . Her pulse beats like a hammer at the wrist, and there's a very high color on her face ." Millard Fillmore's second annual message to Congress, submitted in December 1851, gave double the amount of space to filibustering activities than the brewing sectional conflict . The eagerness of the filibusters, and the public to support them, had an international hue . Clay's son, diplomat to Portugal, reported that Lisbon had been stirred into a "frenzy" of excitement and were waiting on every dispatch . </P>

How many settlers had expanded west by the beginning of the war of 1812