Manifest destiny

• 1. Introduction

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  Manifest destiny shaped the territorial boundaries of the United States across the 19th century and left consequences that reach into the present day. In 1845, a newspaper editor named John O'Sullivan published an essay arguing that it was "our manifest destiny to overspread the continent allotted by Providence for the free development of our yearly multiplying millions." Within months, that phrase had leapt from the editorial page into congressional speeches, party platforms, and war justifications. But the idea itself was always contested. Former president Ulysses S. Grant, who had fought in the Mexican-American War, called it "one of the most unjust ever waged by a stronger against a weaker nation." How did a phrase coined by a single journalist come to define an era of American expansion? And what did it actually mean for the millions of people who stood in its path?

• 2. The Phrase and Its Origins

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  O'Sullivan was an influential advocate for Jacksonian democracy, described by the writer Julian Hawthorne as "always full of grand and world-embracing schemes." His 1839 article predicted a "divine destiny" for the United States rooted in equality, rights of conscience, and personal enfranchisement. That piece never used the words manifest destiny, but six years later his essay in the Democratic Review did. The phrase was meant to urge annexation of the Republic of Texas, but it was O'Sullivan's second deployment of the words, in his newspaper the New York Morning News on the 27th of December 1845, that truly caught fire. There he argued the United States had the right to claim "the whole of Oregon." Ironically, the phrase became widely known only after Whig opponents attacked it. On the 3rd of January 1846, Representative Robert Winthrop became the first member of Congress to use the term in a speech, mocking it as a "new revelation of right." Expansionists embraced the criticism and the phrase both, so quickly that its origins were soon forgotten. Some historians have noted that the original "Annexation" editorial may not have been written by O'Sullivan at all, but by journalist and annexation advocate Jane Cazneau.

• 3. Ideas Behind the Belief

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  Historian Frederick Merk wrote in 1963 that manifest destiny was born out of "a sense of mission to redeem the Old World by high example." Three interlocking ideas sustained it. The first traced back to the Puritan tradition and John Winthrop's 1630 "City upon a Hill" sermon. Thomas Paine echoed this in Common Sense in 1776, declaring "We have it in our power to begin the world over again." The second idea held that the United States had an active mission to spread republican government. Lincoln's Gettysburg Address, which historian Robert Johannsen called "the most enduring statement of America's Manifest Destiny and mission," interpreted the Civil War as a struggle over whether any democratic nation could survive. The third idea was divine election: political scientist Clinton Rossiter described this as a belief that God "bestowed a peculiar responsibility" on Americans to spread the principles of the Bill of Rights. Underneath these three themes ran a darker current. Author Reginald Horsman wrote in 1981 that racial ideology held the American Anglo-Saxon race to be "separate, innately superior" and used to justify "the enslavement of the blacks and the expulsion and possible extermination of the Indians." Historian Frederick Merk noted that these ideas, despite their later association with American nationalism, actually lacked broad national support.

• 4. The Oregon Dispute and Texas

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  The phrase found its most direct political application in two disputes running simultaneously. The Anglo-American Convention of 1818 had established joint occupation of Oregon Country, but by the 1840s thousands of Americans were migrating there over the Oregon Trail. The British had rejected a proposal to divide the region along the 49th parallel and instead wanted the Columbia River as the boundary, which would have claimed most of what later became Washington state. Advocates of manifest destiny demanded all of Oregon up to 54 degrees 40 minutes north latitude, and the Democrats made "All Oregon" a campaign promise in the 1844 election. As president, Polk renewed the earlier 49th-parallel offer. When Britain finally agreed in 1846, fervent expansionists were disappointed. Historian Reginald Stuart noted that "the compass of manifest destiny pointed west and southwest, not north, despite the use of the term 'continentalism.'" The Texas question ran in parallel. The Republic of Texas had declared independence from Mexico in 1836 and sought admission to the United States, which was exactly the process O'Sullivan had envisioned: newly democratic states requesting entry rather than being conquered. But annexation was bitterly divisive because Texas was a slave state. Presidents Andrew Jackson and Martin Van Buren both refused Texas's bid, fearing the slavery debate would tear the Democratic Party apart. Polk tied the two questions together, framing Oregon as a northern counterweight to southern expansion, and won the 1844 election by a slim margin before proceeding to act as though he had a mandate.

• 5. War, Mexico, and Internal Contradictions

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  John Quincy Adams had once been one of the strongest proponents of the ideas underlying manifest destiny. By 1843 he had reversed course, repudiating expansionism because it had become inseparable from the spread of slavery into Texas. The Mexican-American War, which began on the 24th of April 1846, made this tension impossible to ignore. American battlefield successes by the summer of 1847 prompted calls to annex "All Mexico." Senator John C. Calhoun of South Carolina, who had supported annexing Texas, opposed absorbing Mexico for racial reasons. In a speech to Congress on the 4th of January 1848, he declared: "We have never dreamt of incorporating into our Union any but the Caucasian race." This debate exposed the internal contradiction at the heart of the ideology: its racial component argued Mexicans were unfit to become Americans, while its missionary component argued they would benefit from American democracy. The contradiction was never resolved; the controversy ended when the Mexican Cession added Alta California and Nuevo Mexico to the United States, territories more sparsely populated than the rest of Mexico. Historian Frederick Merk argued in his 1963 work Manifest Destiny and Mission in American History that the failure of both the "All Oregon" and "All Mexico" movements showed the concept was far less popular than historians had traditionally assumed. Abraham Lincoln had opposed the war throughout; his "Eulogy to Henry Clay" on the 6th of June 1852, provided what scholars have called the most sustained expression of his reflective patriotism as an alternative to expansionist nationalism.

• 6. Native American Displacement

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  Henry Knox, Secretary of War in the Washington administration, designed the federal policy of purchasing Native American land through treaties. Only the federal government could make such purchases, and whether tribes had a decision-making structure capable of entering a treaty was itself a contested question. Thomas Jefferson believed that Indigenous people were intellectual equals to whites but would inevitably be pushed aside if they did not assimilate. Historian Jeffrey Ostler has noted that Jefferson later advocated for extermination of Indigenous people once he concluded assimilation was no longer possible. In a private letter to William Henry Harrison on the 27th of February 1803, Jefferson described a strategy of drawing tribes away from hunting toward farming, reducing their land use, and gradually acquiring their territory through trade. The Indian Removal Act of 1830, signed by Andrew Jackson, formalized the removal policy. The United States Army, led by generals including William Tecumseh Sherman, Philip Sheridan, and George Armstrong Custer, waged wars against Native peoples who continued to live on land already ceded to the United States by treaty. The Homestead Act of 1862 then encouraged settlement by giving roughly 160 acres to families who would live on and improve the land for five years. Over 123 years, more than 270 million acres were settled under the Act, accounting for ten percent of the total land in the United States. Nick Estes, a Lakota writer, and Onondaga Nation jurist Tonya Gonnella Frichner have linked the ideological roots of manifest destiny to the 15th-century Catholic Doctrine of Christian Discovery and to Chief Justice John Marshall's ruling in Johnson v. McIntosh, in which Marshall held that Indigenous peoples possessed only "occupancy" rights, meaning their lands could be taken by powers of "discovery."

• 7. Beyond the Continent

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  After the Civil War, the phrase manifest destiny briefly revived to justify overseas expansion. Protestant missionary Josiah Strong's 1885 bestseller Our Country argued that America had perfected civil liberty and a "pure spiritual Christianity" and bore a responsibility to the world. The 1892 Republican Party platform explicitly endorsed "the achievement of the manifest destiny of the Republic in its broadest sense." When President William McKinley advocated annexation of Hawaii in 1898, he said, "We need Hawaii just as much and a good deal more than we did California. It is manifest destiny." Former president Grover Cleveland, who had blocked Hawaii's annexation during his own term, called McKinley's move a "perversion of our national destiny." The Spanish-American War of 1898 brought the Philippines, Puerto Rico, Guam, and control over Cuba. The Treaty of Paris required the United States to pay Spain $20 million for the Philippines. The Insular Cases then established that full constitutional rights did not automatically apply to these new territories, effectively creating a two-tier system of American sovereignty. Albert J. Beveridge, speaking in Chicago on the 25th of September 1900, argued that U.S. control was "a blessing to any people and to any land." Frederick Merk later wrote that these colonial acquisitions violated the founding principle that manifest destiny's own proponents had agreed upon: that no people incapable of eventually achieving statehood should be annexed. Puerto Rico, Guam, and American Samoa remain territories today.

• 8. Long Shadows

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  Woodrow Wilson was the first president to use the phrase "manifest destiny" in an annual message to Congress, invoking it in 1920 to argue that the United States had a duty to lead the world toward democracy. His version explicitly rejected territorial expansion and endorsed self-determination. The phrase itself faded from official use after that, replaced in the Roosevelt Corollary of 1904 by the language of an "international police power" in the Western Hemisphere. In 2025, Donald Trump became the first president to use the phrase in an inaugural address, declaring an extension of American influence "into the stars" with ambitions to plant the United States flag on Mars. Historian Daniel Walker Howe has written that "American imperialism did not represent an American consensus; it provoked bitter dissent within the national polity." Frederick Merk offered the sharpest summary of the idea's arc: "The doctrine of Manifest Destiny, which in the 1840s had seemed Heaven-sent, proved to have been a bomb wrapped up in idealism."