Manifest Destiny: The Doctrine that Shaped 19th-Century America

When the United States became an independent nation in the 18th century, a wave of interest reached foreign shores. From intellectuals to politicians, many sought to understand what had happened in the former British colony, and many more wondered how the so-called “American experiment” could be replicated in other nations. The United States led the way in the Age of Revolutions, but it also took on a distinctive role for itself: a mission to expand American virtues and ideals across North America, and eventually, the world. This cultural belief evolved into a doctrine that dominated 19th-century American politics and society: Manifest Destiny.

In 1776, the United States Declaration of Independence was proclaimed by the Second Continental Congress during the American Revolution. Later, in 1783, after years of war, the United States of America became a free nation after defeating the British. The Thirteen Colonies were no more; instead, a new, large-scale form of government was attempted. A democratic federal republic was adopted, where a permanent constitution became a fundamental part of governance, and fundamental rights were also granted. These, alongside other principles, virtues, and ideals, became the cornerstone of the American way of life, which would be thoroughly defined through the belief in “American exceptionalism.”

The idea of America as a unique nation with a particular mission thus became increasingly common and prominent in the public sphere, but crucially, it became a dominant belief among American leaders. This belief went on to evolve into a more active doctrine that wasn’t initially broadly supported but went on to become the centerpiece of American foreign relations and ambitions throughout much of the continent. For many, the belief represented the opportunity of creating a better society, one based on the American way of life, which, at the same time, would serve as an example for Europe.

Though greatly romantic and idealistic, Manifest Destiny also had a real, more complex side. The doctrine’s ideals were conscious of what it meant to create a better life in lands that already had lives going about. American westward expansion, for example, resulted in the genocide of Native Americans, as well as the forced relocation (or at times voluntary but manipulated) of many more. To the south, the conflicts with Mexico and the eventual outbreak of a declared war also resulted in unfair and bloody consequences for both nations.

The idea of Native American removal originated and was promoted before America was even born. The removal of American Indian Nations and peoples, as well as the killing of many of them, was a key part of the westward expansion and Manifest Destiny. Though based on a particular belief, the expansion was also the result of record population growth on the East coast due primarily to European immigration. Hence, the newly arrived immigrants who sought to live a better life in America followed the expansion of the country’s boundaries immediately behind.

Many white settlers and proponents for expansion worried that Native Americans would prove to be obstacles to their land ambitions. Many thought that Native Americans stood in the way of progress and civilization; many white settlers assumed they were uncivilized “savages” who made no good use of the land they possessed. These proponents of expansion pressured the American federal government to remove the Native Americans from their lands and give them instead to the new settlers.

The federal government complied with said demands, as the belief that native lands were not achieving their full potential was widespread. President Andrew Jackson, for example, justified the expansion of America and the “Indian Removal” by understanding it as an extension of the American area of freedom and the fulfillment of the nation’s ideals. He defined aggressive actions through greatness and not through necessary sacrifice; it was a duty, not a chore. Though one of the first to articulate the basis of Manifest Destiny, Jackson wasn’t the last to build on the doctrine.

The United States government was willing to make compromises in its advances, but at all times, it considered its cause fair, just, and mandated. To fully achieve its destiny, America had to eliminate those who stood in the way of progress. Native Americans, according to the US government, were not part of the equation of success of the American way of life. Hence they were removed from their lands and forced to relocate west of the Mississippi, being “allowed” to pursue their own ways. In reality, they were primarily given a choice between two options: assimilation or extermination.

In addition to westward expansion and the forced removal of Native American tribes, the United States sought to expand its borders by looking at its neighbor in the south. Mexico had undergone a similar independence struggle only a few decades after the United States. By 1821, Mexico was an independent country more than twice the size of America but consumed by internal turmoil and frequently threatened by external interventions.

The land gained by Mexico with its independence from Spain was so vast that the weak central government could barely administer it. Instead, only the regional governments held sufficient power to protect themselves and their interests. Furthermore, like the Americans, Mexico was also hostile to the Native Americans who inhabited what the Mexican government considered their legitimate lands.

Unable to manage them effectively, the Mexican lands in the way of the United States’ ambitions eventually became cause for conflict. Tens of thousands of “Anglos”—white, English-speaking Americans—as well as many white European immigrants, had settled into Mexican territory, primarily Texas. The US government favored this position as it provided them with potential causes for tensions and, eventually, annexation. These causes did eventually appear when the successful Texas Revolution led the newly independent nation of Texas to be annexed by America by their choosing.

In 1846, American President James K. Polk found a casus belli to invade Mexico when American military forces were attacked on disputed land. Thus, the Mexican-American War began, a conflict that led to a dramatic increase in America’s borders and its positioning as the main hegemonic power on the continent. Although not everyone in the United States agreed to the “wicked” war, namely the Whigs opposed it, a surge in patriotism and the fulfilled promise of Manifest Destiny made the United States’ ambitions unstoppable.

The expansionist ambitions of the United States were, on many occasions, closely linked to the institution of slavery. Especially during the 19th century, slavery was a driving factor in the political dynamics of America. By the 1850s, tensions were as high as ever, as any further United States territorial expansions meant the topic of slavery would rise again and stir debate.

In the case of the Texas Revolution, for example, America had a keen interest in annexing the Texan territory. Thus, thousands of Anglos and immigrants began settling in Mexico, which initially allowed the influx of said settlers.

However, most American settlers came from the neighboring southern US states, where slavery was allowed, and thus brought thousands of enslaved people into Mexico with them. However, Mexico had outlawed slavery years before. The settlers eventually rebelled, not least because of slavery. The rebels won, and the Texas Republic briefly became an independent nation since the American political climate didn’t immediately allow Texas to enter the union.

At the time, northern states forbade slavery while southern states allowed it. To keep the balance of power between the two sides, the number of “slave” and “non-slave” states had to remain equal. Since Texas allowed slavery, it couldn’t join the US until a “non-slave” state was also added.

Thus, every new territorial addition for the United States meant slavery was back on the table for discussion. Tensions continued to rise until the outbreak of the American Civil War. Manifest Destiny had planted the seeds for rising tensions, with many standing against slavery also opposing reckless expansionism, such as President Abraham Lincoln, who opposed the Mexican-American War. Furthermore, Manifest Destiny was undoubtedly driven by slavery, as the American expansionist machine was fueled by slavery.

Manifest Destiny was the initial chapter of a larger story of American expansionism and hegemony. By the end of the 19th century, there was little room in North America for the United States to take without major consequences or conflicts. Thus, America turned its attention towards different shores and different actions. Namely, the United States made use of its new position as a major power to police the continent and fulfill its own national interests. Through a new interpretation of the Monroe Doctrine, the United States intervened in Latin America to secure its interests. The Monroe Doctrine was first articulated by President James Monroe as a foreign policy opposing European colonialism in the Americas. It claimed to work in the interests of the US’ neighbors, but instead, the doctrine functioned at times more like a new brand of Manifest Destiny. America assumed the position of necessary interceder, arguing that if they didn’t intervene, European powers would.

Although little territory was gained through this policy, the new American attitude allowed for significant gains, such as the acquisition of the Panama Canal. What Manifest Destiny did for raw power potential, new policies such as the Monroe Doctrine did for more polished leverage and control. By the 20th century, America had a more careful approach to foreign policy. The aftermath of the First World War and the ongoing Great Depression led America to pursue a predominantly isolationist foreign policy.

Manifest Destiny is one of the major puzzle pieces necessary to assemble the general picture of America as a country. Beginning with the birth of the nation, its repercussions can be felt even today. A decisive policy with complex and controversial angles, Manifest Destiny is crucial for understanding the United States’ historical landscape and deciphering the modern stage it stands on now.