Manifest Destiny: ‘From Sea to Shining Sea’

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The United States of America was founded on a number of idealistic creeds. Its Revolutionary War was supposedly fought for democracy against foreign imperialism. Its Declaration of Independence supported the principle that “all men are created equal” and equally deserving of the right to “life, liberty and the pursuit of happiness”. Such American idealism would be replicated in the principle of Manifest Destiny – the belief that the USA would inevitably expand “from sea to shining sea” – the core ideological impetus behind 19th Century American westward expansion.

Fundamentally, Manifest Destiny believed in the exceptionality of the American nation and the necessity to spread this ‘greatness’ over the whole continent. Yet its development was by no means destined, and its history was one fraught with controversy.

The America which seized its independence from Britain was mostly confined to a narrow strip on the east coast, yet even before the idea of ‘Manifest Destiny’ had truly been codified, the United States pursued a policy of rapid expansion. In 1803, the American government purchased the Louisiana territory (stretching from New Orleans to Montana) from France for $15 million ($400m in today’s money). Whilst this doubled the US’s nominal size, in truth most of the territory was sparsely populated and controlled by Native Americans. The sale thus provided the right to future expansion and conquest.

Similarly, the 1818 Treaty between the US and Britain, whereby they agreed to joint control over Oregon Country in the Pacific Northwest, shows the extent of the expansionist mission. From the east coast to the west, from the south to the north, America sought control ‘from sea to shining sea’.

This principle of expansion becoming increasingly relevant in the following decades, and by the late 1830s and 1840s, expansionism was one of the most crucial political issues of the day. Indeed, the outcome of the 1844 Presidential election arguably revolved around this issue. Martin Van Buren, the presumptive Democrat Presidential nominee, lost the Democratic nomination due to his opposition to the annexation of Texas. It was instead promptly won by James K. Polk, an ardent expansionist, who defeated the Whig candidate (Henry Clay) in the Presidential election that same year.

Nonetheless, despite the political influence of expansionism, it was only during the following year, in December 1845, that the term Manifest Destiny was finally coined. An editorial for the New York Morning News on the Oregon debate – the Anglo-American dispute over sovereignty in the Pacific Northwest – noted:

“We have a still better [entitlement] than any that can ever be constructed out of all these antiquated materials of old black-letter international law … 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.”

This first explanation of Manifest Destiny encapsulates the view of its proponents. They saw the US, its principles and institutions as a shining example of democracy and liberty, and believed that the best way to spread such brilliance to the peoples of the rest of North America was through conquest. Critically, as destiny implies, they thought that their success was divinely ordained. The phrase itself helped to crystallise this almost romantic and mystical motivation.

The term caught on quickly: it was used again by the Representative for Massachusetts in the Congressional debate on Oregon within the week, and soon became the buzzword used on both sides. Whilst the Oregon debate was settled shortly in June 1846 (with a compromise, whereby the US got everything below the 49th parallel and British colonies everything above), the term remained prominent in the years to come.

Despite the expansionists’ fervent belief that westward expansion was good and necessary, this position was far from axiomatic in US politics at the time. Many saw westward expansion as a destabilising force, as the addition of new states to the union promised to upset the delicate balance of power between ‘free’ and ‘slave’ states.

As such, Northern Democrats and the entire Whig Party were hesitant about such expansion, particularly the annexation of Texas, as they feared that it would increase the power of the southern ‘slave’ states. Though Polk did win in 1844 on an expansionist platform, his mandate was hardly resounding – winning by one state – and the annexation only passed the Senate by two votes – emblematic of the divisions at the time.

Moreover, Manifest Destiny – whilst supposedly a divine mission to spread American ideals – had insidious implications. Though the territorial acquisition in Oregon was peaceful, Manifest Destiny also motivated the Mexican-American War of 1846 that directly followed. Polk sought to add New Mexico and California to the union, and thus escalated local tensions. War finally broke out on May 1846 after a provocative American occupation of the Rio Grande River which saw 16 US troops killed.

US territorial acquisitions over time.

The disorganisation of the Mexican army allowed the US to win their desired territorial concessions from Mexico by 1848 and by this point, the territory of the contiguous continental US had the same borders as it does today. The federal government had thus completed its mission to make their nation span the whole width of the continent. However, most of the west remained sparsely populated and scarcely developed.

Indeed, the romantic notion of Manifest Destiny was often subordinate to material concerns. The fertile land of California and other commercial opportunities were at the forefront of Polk’s mind as he instigated war against Mexico. Such actions suggest Manifest Destiny was more of a post hoc rationalisation of westward expansion for commercial and political power than a genuine idealistic motivation. Indeed, it was only truly in the minds of ordinary Americans who emigrated west that Manifest Destiny was perceived as such a glorious opportunity.

Many of those who headed west were poor and unhappy in their existing lives in the east, and saw the frontier as the ultimate chance to make something of themselves. The attitude and motivation of these migrants to the ‘Wild West’ was summed up in 1865 by Horace Greeley, a New York Daily Tribune journalist, who famously advised his readers: “Go West, young man, go West and grow up with the country.”

The federal government accelerated this westward movement of the frontier with the 1862 Homestead Act, which promised 160 acres of government land to individual farmers, generally to the west of the Mississippi and the ongoing Civil War.

The legislation was passed the same year as the Pacific Railway Act, which granted land to firms building the transcontinental railroad and authorised them to take resources from the surrounding area. These two acts proved to be some of the most influential pieces of legislation in American history, as 1.6 million homesteaders claimed farms and more than 155 million acres of public land – more than 10% of the USA’s total land mass – was given away over the next half-century.

There is a certain romantic vision within such legislation – the US government supported the cause of small, independent farmers striking out on their own, and the building of railroads to connect America’s now-vast expanse. However, the gains of these homesteaders were necessarily founded on the oppression of Native Americans.

The ‘unsettled’ land in the west that the government gave away was in fact home to many Native American tribes. This included both tribes themselves native to the Great Plains and Far West, as well as those displaced from their land in the east to ‘Indian Territory’ by the 1830 Indian Removal Act. The envisioned settlement of the continent by white Americans was blatantly dismissive to Native American land claims.

Indeed, the impact of westward expansion on Native Americans was indisputably severe. Most Native American tribes on the Great Plains led lifestyles dependent on hunting buffalo – a practice impeded by the creation of farms. Grants to railway companies to construct the Transcontinental Railroad, and these companies’ exploitation of the land through forestry and mining, caused even greater disruption.

This is before considering the appropriation of Native land by the government for white settlers. This was often done by treaty, such as the successive Treaties of Fort Laramie, Fort Wise and Medicine Lodge, throughout the 1850s and 1860s. Where such land could not be won through inequitable treaties, the government simply took it force, leading to the Plains Wars of 1851 to 1877.

As a result of westward expansion and the Manifest Destiny which inspired it, Native Americans lost the vast majority of their land to white settlers. By 1879, tribes from across the entire country had been relocated to the very last remnants of Indian Territory – in present-day Oklahoma – that had once covered most of the western United States. However, the settlers’ thirst for more land meant that even this was not safe. White settlers poured in illegally nonetheless, and thousands waited for the sounding of a pistol on the official opening of Oklahoma to land claims on 22 April 1889 so they could seize their plot. The Census Bureau even described it as the “fastest ever settling of a territory”.

By 1890, the same US Census Bureau declared the frontier to be closed. There was no longer any possibility for westward expansion. The continent – from sea to shining sea – had finally been conquered. Manifest Destiny had been realised.

Yet the way Manifest Destiny developed was a far cry from its romantic and idealistic characterisation. Though opposition to expansionism was not fervent, there was a limited mandate for such policies in the first place. Moreover, while it allowed for the spread of American virtues and principles across the continent through the development of the frontier and the rugged individualism of the settlers, its treatment of Natives exposed America’s dark, uncaring underbelly too.

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Fellows, N., Wells, M., 2019. Civil Rights in the USA 1865 – 1992. Hodder Education.

Immerwahr, D., 2019. How to Hide an Empire: A History of the Greater United States. Macmillan.

Isenberg, A.C, and Richards, T., 2017. “Alternative Wests: Rethinking Manifest Destiny.” Pacific Historical Review, 86(1), 4–17.

Jones, M.A., 2013. The Limits of Liberty: American History 1607-1992. Oxford University Press.

Pratt, J.W., 1927. “The Origin of ‘Manifest Destiny.’” The American Historical Review, 32(4), 795–798.