Written by Eva Beere
“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.”
–John L. O’Sullivan, New York Morning News, 1845.
‘Manifest Destiny’. This phrase was first coined by newspaper editor John O’Sullivan in 1845, articulating the belief in America’s divinely destined mission to expand westwards and spread democracy across the continent. Writing in support of the annexation of Texas and the acquisition of the Oregon Territory, O’Sullivan finally put a long-standing, but previously vague American ideology into words. The belief behind Manifest Destiny had been present from the founding of the United States in 1776, and once articulated by O’Sullivan, was used to justify a series of violent land grabs, from the brutal removal of Native American tribes from occupied territories to the war with Mexico to the occupation of Cuba. What started as a means to expand American territory westwards has seeped into the nation’s heart and continues to justify much of America’s current-day foreign policy.
The inception of Manifest Destiny can be traced back to the Treaty of Paris in 1783 which recognised the United States as an independent nation, thus concluding the American Revolution. The treaty was surprisingly generous, whereby Britain ceded a vast majority of land known as the Northwestern territory to the United States, including the present-day states of Ohio, Michigan, Indiana, Illinois, Wisconsin and parts of Minnesota, doubling the size of the colonies. By defining the clear boundaries of United States territory, the Treaty set the groundwork for future westward expansion by stipulating that the Western boundary would be open for navigation by American and British forces. In this way, the three American negotiators John Adams, Benjamin Franklin, and John Jay established the United States on an inherent contradiction; the United States arose as a nation free from European colonial rule, but also as one destined by God to expand westwards and overseas.
The Louisiana Purchase of 1803 set the precedent for American expansionism throughout the nineteenth century. The worsening situation in Haiti coupled with increased French interest in India prompted Napolean to sell the entirety of the Louisiana Territory to the United States for just fifteen million dollars. This purchase doubled the size of the United States, incorporating the present-day states of Louisiana, Arkansas, Missouri, Iowa, Oklahoma, Kansas, Nebraska, North Dakota, South Dakota, and parts of Minnesota, New Mexico, Montana, Wyoming, and Colorado into the union.
The acquisition of 828,000 square miles of new land sparked a determination amongst Americans to expand their frontiers, especially southwards towards Texas and New Mexico. In 1804, Captain Meriwether Lewis and Second Lieutenant William Clark led the federally funded Corps of Discovery expedition to investigate the newly acquired land from the Louisiana Purchase. Commissioned by Thomas Jefferson, the expedition attempted to declare United States sovereignty over the land previously occupied by Native American tribes. Returning in 1806 with maps of uncharted lands, rivers and mountains, the Lewis and Clark expedition sparked desire amongst the American people for land and economic prosperity in the West.
Whilst many Americans moved westwards, the United States government attempted to reduce Spanish colonial power in surrounding territories, which was weakened due to emerging revolutionary movements across Latin America. In 1818, Jackson invaded Spanish-controlled Florida, which ended in Spain ceding East Florida to the United States on the condition they pay five million dollars for the damage they caused. Furthermore, in 1819 Spain signed the Transcontinental Treaty which saw Spain surrender their rights to Oregon in exchange for the United States surrendering their rights to Texas.
Texas became the battleground for fighting between United States and Mexican forces in the 1840s. Whilst Texas had been placed under Mexican control in 1821, in 1836 Texas became independent and petitioned to join the United States as a slave state. Nevertheless, Mexico attempted to keep Texas attached to the Mexican Republic. As more Americans moved westwards, into territories such as Texas, further momentum was added to this independence movement. In July 1845, Polk ordered commander Zachary Taylor to move forces into the lands between the Nueces and Rio Grande rivers, sending instructions to purchase lands along the Texan Mexican border. The failure of Taylor’s mission led Polk to declare war on Mexico a month later.
A key military campaign of the Mexican American war was the Conquest of California. American interest in Mexican California predated the war when Colonel John C. Frémont, commissioned by the US government, crossed the Sierra Nevada mountains into Sacramento Valley in California. Frémont would later lead a battalion to capture major cities in Southern California, such as Santa Barbara and Presidio. He also signed the Treaty of Cahuenga, ending the Mexican war in California after the Californians surrendered in January 1847. Coupled with Frémont’s expedition, California became even more desirable after James W. Marshall discovered copious amounts of gold in Sutter’s Mill in Coloma, California, triggering a mass influx of settlers into the ‘gold state.’ In pursuit of economic wealth, thousands of indigenous Californians were massacred by Eastern settlers. Between 1848 and the 1860s, the California genocide reduced the population of California’s native people from 150,000 to 20,000. The Mexican American War was ended by the Treaty of Guadalupe Hidalgo when Mexico ceded 525,000 square miles to the US including present-day California, Nevada, Utah and New Mexico, in exchange for fifteen million dollars. In the words of M.B. Deopujari “Mexico fell victim to Manifest Destiny,” whereby the United States’ newfound hunger for land and power resulted in a loss of Mexican territory.
An unfortunate consequence of American expansion was the brutal assault and massacre of the Native American tribes across the Midwest. Manifest Destiny was deeply intertwined with a belief in American superiority, reinforcing the need to spread democracy westwards. Thus, as United States settlers moved into lands that would later become Mississippi and Alabama, the main obstacle they faced was the Indian tribes who resided in these areas. Throughout President Jackson’s presidency, the United States government and American colonisers made an effort to enforce a system of racial supremacy in new territories, forcibly removing Native peoples from the Southeast. The Indian Removal Act of 1830, signed by President Andrew Jackson, authorised the United States government to remove Native Americans from their home territories in the East and relocate them to United States government-designated lands. Throughout Jackson’s presidency, some 50,000 Indians moved into Indian Territory, a journey called ‘The Trail of Tears.’ Between 1816 and 1840, tribes such as Cherokees, Chickasaws, Choctaws, Creeks, and Seminoles living between Michigan and Louisiana made the deadly journey to lands West of Mississippi.
This aggressive expansionism persisted into the late nineteenth century, as Americans turned their attention abroad in search of their new frontier. The Monroe Doctrine, a United States foreign policy which opposed European colonialism in the Western hemisphere, became a driving force in United States decision-making abroad. This resulted in the annexation of Hawaii in 1898 and the outbreak of the Spanish War in April 1898. The Spanish war ended in December 1898, when Spain and the United States signed a peace treaty in Paris which declared Cuba an independent territory, ceded Puerto Rico and Guam to the United States, and allowed for the Philippines to be purchased for twenty million dollars. This war marked a shift in United States territorial conquest from non-colonial to colonial; before 1898 newly annexed white citizens had been granted the privileges of United States citizenship and full political rights, yet these rights were not extended to the non-white citizens in the newly colonised Latin American countries.
Although the phrase Manifest Destiny declined in usage at the turn of the twentieth century, ideas of American expansionism were simply replaced by interventionist tactics as America attempted to secure their interests abroad. In his 1901 speech, Woodrow Wilson emphasised the spirit of American exceptionalism, praising the constant determination of the Americans to find new frontiers for economic development and push the limits of American success. In portraying America as an undefeatable nation, he encouraged a continuation of this undeniable determination, saying “This great pressure of a people moving always to new frontiers, in search of new lands, new power, the full freedom of a virgin world, has ruled our course and formed our policies like a Fate…‘Who shall say where it will end?’” This spirit was particularly present during World War I, when Woodrow Wilson commissioned United States forces to enter the war and help rebuild peace in Europe.
Trump reignited the American dream of global expansion in his 2025 Inaugural Speech, claiming that “the United States will once again consider itself a growing nation — one that increases our wealth, expands our territory, builds our cities, raises our expectations, and carries our flag into new and beautiful horizons.” Acting as the first president to mention the term ‘Manifest Destiny’ in an inaugural speech, his first weeks in office have demonstrated that his claims to use military force as a means to occupy Greenland and the Panama Canal are not attention-seeking comments, but instead, a means to continue the American expansionism of the 1800s. As Trump stirs up fears concerning territorial ambition and US nationalism, Wilson’s question echoes in the minds of many: Who shall say where it will end?
Bibliography
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Deopujari, M.B. “AMERICA’S MANIFEST DESTINY & MEXICO.” Proceedings of the Indian History Congress 28 (1966): 489–94. http://www.jstor.org/stable/44140483.
Greenberg, Amy S., ‘US Expansionism during the Nineteenth Century: “Manifest Destiny”’, in Peter Fibiger Bang, C. A. Bayly, and Walter Scheidel (eds), The Oxford World History of Empire: Volume Two: The History of Empires (New York, 2021; online edn, Oxford Academic, 23 Dec. 2021)
Limerick, Patricia Nelson. “The Gold Rush and the Shaping of the American West.” California History 77, no. 1 (1998): 30–41. https://doi.org/10.2307/25462460.
Smithsonian Institution Archives. “Frémont Expedition to Oregon and California (1843 – 1844).” Record Unit. Smithsonian Institution Archives, Washington, D.C.
Wilson, Woodrow. “The Ideals of America.” The Atlantic, December 1902. https://www.theatlantic.com/magazine/archive/1902/12/the-ideals-of-america/376192/.
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