Manifest Destiny: Geopolitical Doctrine behind U.S. Expansion

Unveiling Manifest Destiny: America's Quest for Power

Manifest Destiny was a 19th-century political and geostrategic doctrine promoted by a group of white American politicians and businessmen, primarily of British descent. Rooted in American Exceptionalism and Romantic Nationalism, they claimed divine authorization to spread democracy and capitalism across the entire North American continent.

This mandate justified the removal or destruction of the native population and claiming control of British and Spanish territory. Although the doctrine significantly influenced subsequent key U.S. national leaders, it eventually collapsed, marking the dawn of noteworthy political dominance for the United States, launching it onto the world stage as the main hegemonic power on the continent. 

This painting represents the idea of Manifest Destiny - the belief that the United States should expand westward across the continent, from the Atlantic to the Pacific Ocean.

Image Credit: Wikimedia Commons, American Progress (John Gast painting)

Over time, American leaders made Manifest Destiny a significant aspect of politics. The term itself suggests something obvious and certain — "Manifest" means clear, and "Destiny" means something bound to happen. Together, it's like saying it's our fate, something that's sure to happen. 

In this article, we will explore a complete analysis on Manifest Destiny and its consequences in terms of history and geopolitics.

💻 Table of Contents:

Tracing the Ideological Origins of Manifest Destiny
Manifest Destiny: Political Disagreement and Debate
Manifest Destiny, Slavery Conflict & Role of Abraham Lincoln
Slavery Flashpoint in the Age of Manifest Destiny
Manifest Destiny: Linking East and West
The Louisiana Purchase: Groundwork of the Manifest Destiny
The Significance of Texas Annexation and Manifest Destiny
The Oregon Territory Dispute and the Expansion of Manifest Destiny
The Forced Relocation of Native Americans
The End of Manifest Destiny:  Assessment of a Triumph Painted by Tragedy

Tracing the Ideological Origins of Manifest Destiny:

To understand about Manifest Destiny more briefly, we must know the two definitions that mentioned in the prelude: American exceptionalism and Romantic nationalism.

American Exceptionalism is the belief that the United States is fundamentally different or special compared to other countries. Propagators argue that America's values, political system, and historical development are unique and superior. They often believe that the U.S. has a distinct role in leading and improving the world.

And Romantic nationalism is the belief that each nation possesses a unique identity and culture that should be celebrated and preserved. It emphasizes a strong sense of national pride and loyalty, often rooted in historical myths, cultural traditions, and folklore. This ideology emerged in the late 18th and early 19th centuries, promoting the idea that a nation's character and spirit are distinct and worthy of protection.

After the United States gained independence in the 18th century, people worldwide grew curious about the new nation's success. Fueled by the Monroe Doctrine's influence, the USA embraced a distinct ambition to expand its territory while promoting its values and ideas under the guise of Divine Authorization, spreading democratic governance and capitalism. 

Before the rise of Manifest Destiny, present-day U.S. states like Texas, California, Nevada, Utah, Arizona, New Mexico, and Colorado were under Mexican or other foreign control. The ideology of Manifest Destiny, advocating for U.S. expansion across North America, motivated the Mexican-American War. Following the U.S. victory in 1848, the Treaty of Guadalupe Hidalgo transferred over 525,000 square miles of territory to the United States, encompassing Arizona, California, western Colorado, Nevada, New Mexico, Texas, and Utah. 

This acquisition was seen as the realization of Manifest Destiny, providing vast resources and growth potential. California's fertile lands and the Gold Rush, which aligned perfectly with the goals of Manifest Destiny, catalyzed significant economic expansion. This territorial gain marked a major step towards America's vision of continental dominance, offering abundant natural wealth and opportunities.

Manifest Destiny: Political Disagreement and Debate

Manifest Destiny was a divisive political concept in the 19th century United States. It was used to support the expansion of the country westward, often at the expense of Native American populations. The term "Manifest Destiny" emerged and became a key campaign issue in 1844. The Democrats won that year's presidential election. James Knox Polk entered the presidency with a clear plan for westward expansion. He promised not to seek a second term, and kept his word.

The Democrats used Manifest Destiny to justify actions like the annexation of Texas as a slave state and the Mexican-American War. Historian Daniel Walker Howe concludes that American imperialism did not represent a national agreement, but rather provoked significant dissent and division within the country at the time.

The term "Manifest Destiny" was first used by newspaper editor John O'Sullivan in 1845 to promote the annexation of Texas and the acquisition of the Oregon territory. However, some historians suggest that the unsigned editorial in which the phrase first appeared was actually written by journalist and annexation advocate Jane Cazneau.

Manifest Destiny is viewed differently depending on perspective. For many Americans at the time, it represented progress and the spread of democratic ideals. However, for Native Americans and other indigenous peoples, it led to displacement, suffering, and loss of life and culture, making it a controversial and often criticized concept. 

Additionally, the expansionist vision of Manifest Destiny crashed with the moral dilemma of slavery, contributing to deep divisions within American society. Notably, many Whigs and prominent Republicans like Abraham Lincoln and Ulysses S. Grant strongly opposed these expansionist policies. Even some early supporters, like former President John Quincy Adams, later rejected Manifest Destiny because it enabled the expansion of slavery. Grant, who fought in the Mexican-American War, condemned it as an "unjust" conflict against a weaker nation.

This image depicts the landing of American forces under General Winfield Scott during the 1847 invasion of Veracruz, Mexico, a key event in the expansionist vision of Manifest Destiny.

Image Credit: Wikimedia Commons, Landing of the American forces

Manifest Destiny, Slavery Conflict & Role of Abraham Lincoln:

Manifest Destiny, the 19th-century belief that the United States was designed to expand across North America, brought significant political and social conflict, particularly concerning the expansion of slavery. 

As the nation acquired new territories, the question of whether these areas would permit slavery became a central and contentious issue, driving a division between the Northern and Southern states (The Confederacy, formed by 11 states that had separated from the Union) and leading to a series of conflicts that foreshadowed the devastating American Civil War (1861 –1865). To more clear, let's move to history back: 

Before the American Civil War (1861-1865) or during the "Age of Manifest Destiny" (1812-1867) or American Territorial Extension Concept, the United States was a union of 50 states. However, in 1860-1861, 11 southern states separated from the Union (The United States of America) and formed the Confederate States of America, seeking to establish an independent nation that would preserve the institution of slavery.

Abraham Lincoln (Presidential period: 1861-1865), as President of the United States, was determined to preserve the integrity of the Union and prevent the country from splitting apart. The goal of the Union forces in the Civil War was to defeat the secessionist Confederate states and reunite the country under a single federal government.

So when Lincoln is described as preserving the Union during the Civil War, it means he led the successful effort to keep the United States together as one nation, rather than allowing it to be permanently divided into separate northern and southern entities. Maintaining the Union was a core objective that Lincoln staunchly defended throughout the conflict. And Abraham Lincoln was successful in this monumental endeavor.

Notably, President Abraham Lincoln opposed certain aspects of Manifest Destiny, criticizing the anti-immigrant nativism and overly aggressive imperialist policies that he viewed as unfair and unreasonable. Abraham Lincoln's pivotal role in preserving the Union and abolishing slavery solidified his iconic status as one of the most important and admired figures in American history.

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Slavery Flashpoint in the Age of Manifest Destiny:

The rapid expansion of the United States during the era of Manifest Destiny ignited intense debates over the future of slavery in the new western territories. As the nation grew, the controversial issue of whether these lands would allow or prohibit slavery became a flashpoint, threatening to split the country apart and paving the way for the American Civil War.

The Missouri Compromise and its Aftermath:

The Missouri Compromise of 1820 marked the beginning of the intense debates over slavery in new territories. Missouri's application for statehood as a slave state threatened to disrupt the balance of power between free and slave states. 

The compromise allowed Missouri to enter as a slave state and Maine as a free state while establishing the 36°30' line ("thirty-six degrees, thirty minutes line") to limit the spread of slavery in the Louisiana Purchase territory. While temporarily successful, the compromise revealed the deep divisions and set the stage for future conflicts.

Wilmot Proviso and the Mexican-American War:

The Wilmot Proviso was a key piece of legislation proposed by Democratic Congressman David Wilmot of Pennsylvania in 1846 during the Mexican-American War that forbid slavery in any territory acquired from Mexico acquired by the United States from Mexico through the Treaty of Guadalupe Hidalgo. 

Specifically, the proviso stated that "neither slavery nor involuntary servitude shall ever exist" in any new territory obtained from Mexico as a result of the war. This aimed to prevent the territories gained through Manifest Destiny from becoming new slave states.

The Wilmot Proviso represented a direct challenge to the expansion of slavery, which had become a major source of disagreement between the Northern and Southern states. It reflected the growing antislavery sentiment in the North, who wanted to limit the spread of the society of slavery.

The proviso was passed by the House of Representatives but ultimately failed in the Senate, largely due to opposition from Southern politicians who were determined to protect the expansion of slavery. This failure highlighted the deep divisions over the slavery issue that was tearing at the fabric of the Union.

Although the Wilmot Proviso did not become law, it was an important precursor to the major conflicts over slavery that would culminate in the American Civil War just over a decade later. It demonstrated the irreconcilable differences between the North and South on the question of slavery's expansion.

The Compromise of 1850:

The Compromise of 1850 attempted to address the status of slavery in the new territories gained from Mexico. It included admitting California as a free state, allowing Utah and New Mexico to decide on slavery through popular sovereignty, and implementing a stricter Fugitive Slave Law. 

Despite temporarily easing tensions, the compromise's components, particularly the controversial Fugitive Slave Act of 1850, sparked widespread controversy and resistance in the North, intensifying sectional hostilities and demonstrating the fragile nature of such agreements.

Kansas-Nebraska Act and "Bleeding Kansas":

The Kansas-Nebraska Act of 1854, proposed by Senator Stephen A. Douglas, allowed the settlers of Kansas and Nebraska to decide the legality of slavery through popular sovereignty, effectively cancelling the Missouri Compromise.

This led to violent clashes between pro-slavery and anti-slavery settlers in Kansas, a period known as "Bleeding Kansas." The violence and chaos underscored the deep divisions and the failure of popular sovereignty as a solution, further polarizing the nation.

Dred Scott Decision:

The 1857 Dred Scott v. Sandford Supreme Court decision intensified the conflict over slavery. The Court ruled that African Americans could not be citizens and that Congress lacked the authority to prohibit slavery in the territories. 

This decision invalidated the Missouri Compromise and was perceived as a significant victory for the pro-slavery faction, further alienating the North and pushing the nation closer to disunion.

Manifest Destiny: Linking East and West

In the 19th century, the belief in Manifest Destiny - the idea that the United States was destined to expand across the continent - led to the construction of the First Transcontinental Railroad. This ambitious engineering project was driven by factors like westward expansion, economic growth, and the need for efficient transportation.

The Pacific Railway Act of 1862, signed by President Lincoln, provided federal support for the railroad's construction. The Central Pacific and Union Pacific companies built the line from opposite coasts, facing significant geographic challenges. Their diverse workforces, including Chinese laborers and Irish immigrants, played crucial roles in completing this landmark endeavor.

The completion of the Transcontinental Railroad in 1869 revolutionized travel and commerce across the United States. By connecting the East and West coasts, the railroad dramatically reduced the time and cost of traversing the vast expanse of the American continent. It facilitated westward expansion and helped solidify the concept of a united country from coast to coast - a true manifestation of Manifest Destiny through business and transportation innovation.

The Louisiana Purchase: Groundwork of the Manifest Destiny

The Louisiana Purchase in 1803 was a pivotal event that significantly expanded the territory of the United States and laid the groundwork for the nation's westward expansion, which was later supported by the doctrine of Manifest Destiny. Initially, France had refused to relinquish control of its North American territories, but when Napoleon faced the prospect of war with Britain, he sought to raise funds. President Thomas Jefferson capitalized on this opportunity, negotiating the purchase of the entire Louisiana Territory for $15 million, which doubled the size of the country.

Uncle Sam uses a magnet labeled "United States Protectorates" to draw Central and South American countries towards him, with Panama already in his pocket, while smoke labeled "Mexico" from the Mexican Revolution rises in the background.

Image Credit: Wikimedia Commons, Modified by: Time Printer, Monroe Doctrine

The acquisition of over 800,000 square miles of land west of the Mississippi River was not without its critics, who questioned the constitutional legitimacy of such a move. However, the strategic importance of securing the vital Mississippi River and the port of New Orleans for trade proved to be a significant factor in Jefferson's decision. 

The Louisiana Purchase opened up the vast western lands for settlement and exploration, fueling the expansionist ambitions of white Americans. Although this westward movement had devastating consequences for Native American populations forced from their ancestral lands, the Louisiana Purchase marked a critical juncture in the United States' transformation into a transcontinental power and the advancement of Manifest Destiny.

The Significance of Texas Annexation and Manifest Destiny:

The annexation of Texas in 1845 was a pivotal event that fueled the belief in Manifest Destiny - the conviction that the United States was destined to stretch from the Atlantic to the Pacific Ocean. It started in the 1820s when Mexico invited American settlers to its northern lands by offering cheap land. Many Americans moved there but soon clashed with Mexico's rules, like converting to Catholicism and rejecting slavery. These tensions led Texas to declare independence from Mexico in 1836.

Texas wanted to join the U.S. quickly, but some in Congress worried about adding another slave state. Despite this, President James K. Polk, who believed in Manifest Destiny, supported annexing Texas. This move was a big step toward expanding the U.S., leading to the Mexican-American War over a border dispute. The war ended with the U.S. gaining large western territories, including California.

This rapid expansion brought growth and challenges. While it boosted the economy with new settlers, resources, and trade, it also increased conflicts with Native Americans and debates over slavery. The Wilmot Proviso, which tried to ban slavery in new territories, highlighted the growing divide that would lead to the Civil War.

The annexation of Texas and the Manifest Destiny agenda significantly shaped the U.S.'s path to becoming a transcontinental power, impacting the nation's political, economic, and social landscape.

The Oregon Territory Dispute and the Expansion of Manifest Destiny:

The dispute over the Oregon Territory was a significant chapter in the unfolding of Manifest Destiny - the belief that the United States was destined to stretch from the Atlantic to the Pacific Ocean. The territory, which encompassed present-day Oregon, Washington, and much of British Columbia, had been claimed by Spain, Great Britain, Russia, and the United States over the course of the 19th century.

The U.S. claim to the Oregon Territory was bolstered by the explorations of Lewis and Clark and the establishment of trading posts like Astoria by John Jacob Astor's Pacific Fur Company. However, the border between the U.S. and British Canada remained unsettled, with neither side willing to compromise on the line of division.

As American settlers increasingly migrated to the Oregon Territory along the Oregon Trail, the issue became politically charged. Proponents of Manifest Destiny, such as President James K. Polk, were eager to settle the boundary and incorporate the territory into the United States. They raised the provocative slogan of "54 degrees 40 minutes or fight," referring to the northernmost boundary claim.

Ultimately, a compromise was reached through diplomacy between the U.S. and Britain. The border was set at the 49th parallel, with some minor adjustments that reserved Vancouver Island for Canada. This settlement, ratified by the U.S. Senate in 1846, marked a significant victory for the Manifest Destiny agenda, as it added vast new lands to the United States' expanding domain.

The resolution of the Oregon Territory dispute, along with the annexation of Texas and the Mexican-American War, demonstrated the unstoppable momentum of Manifest Destiny in the mid-19th century. These events not only expanded the geographic reach of the United States but also heightened tensions over the expansion of slavery, foreshadowing the impending sectional crisis that would culminate in the American Civil War.

The Oregon Territory dispute thus underscores the central role that Manifest Destiny played in shaping the political, economic, and social landscape of the United States during this transformative period of its history.

The Forced Relocation of Native Americans:

In the 1820s and 1830s, the U.S. government implemented a policy of "Indian removal," forcibly relocating Native American tribes from their ancestral lands east of the Mississippi River to areas west of the river, known as "Indian Territory." This was driven by conflicts over land between Native Americans and white settlers, as well as the belief in Manifest Destiny - the idea that the U.S. was destined to expand across the continent.

The removal policy began under President John Quincy Adams, but was codified into law by President Andrew Jackson through the Indian Removal Act of 1830. This authorized the president to negotiate treaties with tribes, exchanging their eastern lands for lands in the west. Some tribes, like those in the Old Northwest, went along with this relatively peacefully. But in the Southeast, the "Five Civilized Tribes" - the Chickasaw, Choctaw, Creek, Seminole, and Cherokee - resisted.

A depiction of indigenous people forcibly relocated from their homelands during Indian removal, with a somber and tragic atmosphere during the era of Manifest Destiny

Image Credit: Flickr, The Struggle against Indian Removal

The U.S. government used coercion, threats, and even the military to force these tribes to relocate. The removal of the Cherokee, known as the "Trail of Tears," was especially infamous, with many dying during the forced march. In total, the U.S. acquired over 450 million acres of land from Native Americans through these forced removals.

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The Indian Removal policy was a dark chapter in American history, resulting in immense suffering and the decimation of Native American populations. It exemplified the nation's push for westward expansion at the expense of indigenous rights and lives.

The End of Manifest Destiny:  Assessment of a Triumph Painted by Tragedy

The United States, founded on idealistic principles such as democracy and equality, pursued a policy of rapid westward expansion known as Manifest Destiny. This belief in the nation's exceptionalism and divine right to spread from the Atlantic to the Pacific drove significant territorial acquisitions. Early expansions included the 1803 Louisiana Purchase from France and the 1818 Treaty with Britain for joint control of Oregon.

Manifest Destiny became a dominant political issue in the 1830s and 1840s, influencing the 1844 presidential election. James K. Polk, an expansionist, won the election and oversaw the annexation of Texas and the Mexican-American War, resulting in the acquisition of New Mexico and California by 1848.

Despite its idealistic rhetoric, Manifest Destiny had insidious implications. It often masked economic motivations and led to the displacement and oppression of Native Americans. The 1862 Homestead Act and the Pacific Railway Act accelerated westward migration but encroached on Native lands, leading to conflicts like the Plains Wars. By 1890, the U.S. Census Bureau declared the frontier closed, marking the completion of Manifest Destiny.

By the late 19th century, the United States had achieved its expansionist dream, becoming a transcontinental power with the acquisition of vast new territories and the incorporation of the Pacific Coast. The California Gold Rush (1848-1855) spurred significant migration and settlement, while the transcontinental railroad integrated these lands into the national economy. 

However, this triumph came at a high cost. The forced removal and subjugation of Native American populations, epitomized by events like the Trail of Tears, and the violation of treaties marked a dark legacy. Moreover, the expansionist fervor fueled tensions over slavery, contributing to the Civil War's outbreak. 

Thus, while Manifest Destiny realized America's continental ambitions, it left a complex and troubling legacy marked by displacement, conflict, and moral compromise.

The idea of Manifest Destiny had also a significant impact on Chinese and Hispanic communities as well. Chinese immigrants faced harsh working conditions and discriminatory laws prohibiting their entry into the country. They also endured violence. 

Similarly, Hispanic citizens experienced land loss and discriminatory legislation, despite assurances of citizenship. They faced unequal treatment and limited opportunities, which led to a sense of division and being treated as second-class citizens.


Manifest Destiny was the driving force behind America's expansion across the continent. It was not a single event or policy, but rather a persistent philosophy that shaped the course of the nation's history.

As an intangible ideology, Manifest Destiny cannot be tied to a specific date or happening. Yet it was the animating spirit that justified America's relentless push westward, the displacement of native populations, and the country's emergence as a transcontinental power. Manifest Destiny was the fundamental driver of American history, a dynamic worldview that fundamentally transformed the land and its people.

Historian Walter McDougall has described Manifest Destiny as a "corollary" of the earlier Monroe Doctrine, highlighting their closely intertwined relationship. Even today, the influential ideas behind these doctrines continue to shape US foreign policy, particularly in promoting democracy and asserting America's role on the global stage.