In 1803, President Thomas Jefferson purchased the territory of Louisiana from the French government for $15 million. The Louisiana Purchase stretched from the Mississippi River to the Rocky Mountains and from Canada to New Orleans, and it doubled the size of the United States. To Jefferson, westward expansion was the key to the nation’s health: He believed that a republic depended on an independent, virtuous citizenry for its survival, and that independence and virtue went hand in hand with land ownership, especially the ownership of small farms. (“Those who labor in the earth,” he wrote, “are the chosen people of God.”) In order to provide enough land to sustain this ideal population of virtuous yeomen, the United States would have to continue to expand. The westward expansion of the United States is one of the defining themes of 19th-century American history, but it is not just the story of Jefferson’s expanding “empire of liberty.” On the contrary, as one historian writes, in the six decades after the Louisiana Purchase, westward expansion “very nearly destroy[ed] the republic.”
Manifest Destiny
By 1840, nearly 7 million Americans–40 percent of the nation’s population–lived in the trans-Appalachian West. Following a trail blazed by Lewis and Clark, most of these people had left their homes in the East in search of economic opportunity. Like Thomas Jefferson, many of these pioneers associated westward migration, land ownership and farming with freedom. In Europe, large numbers of factory workers formed a dependent and seemingly permanent working class; by contrast, in the United States, the western frontier offered the possibility of independence and upward mobility for all. In 1843, one thousand pioneers took to the Oregon Trail as part of the “Great Emigration.”
Did you know? In 1853, the Gadsden Purchase added about 30,000 square miles of Mexican territory to the United States and fixed the boundaries of the “lower 48” where they are today.
In 1845, a journalist named John O’Sullivan put a name to the idea that helped pull many pioneers toward the western frontier. Westward migration was an essential part of the republican project, he argued, and it was Americans’ “manifest destiny” to carry the “great experiment of liberty” to the edge of the continent: to “overspread and to possess the whole of the [land] which Providence has given us,” O’Sullivan wrote. The survival of American freedom depended on it.
Westward Expansion and Slavery
Meanwhile, the question of whether or not slavery would be allowed in the new western states shadowed every conversation about the frontier. In 1820, the Missouri Compromise had attempted to resolve this question: It had admitted Missouri to the union as a slave state and Maine as a free state, preserving the fragile balance in Congress. More important, it had stipulated that in the future, slavery would be prohibited north of the southern boundary of Missouri (the 36º30’ parallel) in the rest of the Louisiana Purchase.
However, the Missouri Compromise did not apply to new territories that were not part of the Louisiana Purchase, and so the issue of slavery continued to fester as the nation expanded. The Southern economy grew increasingly dependent on “King Cotton” and the system of forced labor that sustained it. Meanwhile, more and more Northerners came to believed that the expansion of slavery impinged upon their own liberty, both as citizens–the pro-slavery majority in Congress did not seem to represent their interests–and as yeoman farmers. They did not necessarily object to slavery itself, but they resented the way its expansion seemed to interfere with their own economic opportunity.
Westward Expansion and the Mexican War
Despite this sectional conflict, Americans kept on migrating West in the years after the Missouri Compromise was adopted. Thousands of people crossed the Rockies to the Oregon Territory, which belonged to Great Britain, and thousands more moved into the Mexican territories of California, New Mexico and Texas. In 1837, American settlers in Texas joined with their Tejano neighbors (Texans of Spanish origin) and won independence from Mexico. They petitioned to join the United States as a slave state.
This promised to upset the careful balance that the Missouri Compromise had achieved, and the annexation of Texas and other Mexican territories did not become a political priority until the enthusiastically expansionist cotton planter James K. Polk was elected to the presidency in 1844. Thanks to the maneuvering of Polk and his allies, Texas joined the union as a slave state in February 1846; in June, after negotiations with Great Britain, Oregon joined as a free state.
That same month, Polk declared war against Mexico, claiming (falsely) that the Mexican army had “invaded our territory and shed American blood on American soil.” The Mexican-American War proved to be relatively unpopular, in part because many Northerners objected to what they saw as a war to expand the “slaveocracy.” In 1846, Pennsylvania Congressman David Wilmot attached a proviso to a war-appropriations bill declaring that slavery should not be permitted in any part of the Mexican territory that the U.S. might acquire. Wilmot’s measure failed to pass, but it made explicit once again the sectional conflict that haunted the process of westward expansion.
Westward Expansion and the Compromise of 1850
In 1848, the Treaty of Guadelupe Hidalgo ended the Mexican War and added more than 1 million square miles, an area larger than the Louisiana Purchase, to the United States. The acquisition of this land re-opened the question that the Missouri Compromise had ostensibly settled: What would be the status of slavery in new American territories? After two years of increasingly volatile debate over the issue, Kentucky Senator Henry Clay proposed another compromise. It had four parts: first, California would enter the Union as a free state; second, the status of slavery in the rest of the Mexican territory would be decided by the people who lived there; third, the slave trade (but not slavery) would be abolished in Washington, D.C.; and fourth, a new Fugitive Slave Act would enable Southerners to reclaim runaway slaves who had escaped to Northern states where slavery was not allowed.
Bleeding Kansas
But the larger question remained unanswered. In 1854, Illinois Senator Stephen A. Douglas proposed that two new states, Kansas and Nebraska, be established in the Louisiana Purchase west of Iowa and Missouri. According to the terms of the Missouri Compromise, both new states would prohibit slavery because both were north of the 36º30’ parallel. However, since no Southern legislator would approve a plan that would give more power to “free-soil” Northerners, Douglas came up with a middle ground that he called “popular sovereignty”: letting the settlers of the territories decide for themselves whether their states would be slave or free.
Northerners were outraged: Douglas, in their view, had caved to the demands of the “slaveocracy” at their expense. The battle for Kansas and Nebraska became a battle for the soul of the nation. Emigrants from Northern and Southern states tried to influence the vote. For example, thousands of Missourians flooded into Kansas in 1854 and 1855 to vote (fraudulently) in favor of slavery. “Free-soil” settlers established a rival government, and soon Kansas spiraled into civil war. Hundreds of people died in the fighting that ensued, known as “Bleeding Kansas.”
A decade later, the civil war in Kansas over the expansion of slavery was followed by a national civil war over the same issue. As Thomas Jefferson had predicted, it was the question of slavery in the West–a place that seemed to be the emblem of American freedom–that proved to be “the knell of the union.”
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Manifest Destiny, a phrase coined in 1845, is the idea that the United States is destined—by God, its advocates believed—to expand its dominion and spread democracy and capitalism across the entire North American continent. The philosophy drove 19th-century U.S. territorial expansion and was used to justify the forced removal of Native Americans and other groups from their homes. The rapid expansion of the United States intensified the issue of slavery as new states were added to the Union, leading to the outbreak of the Civil War.
Louisiana Purchase
Thanks to a high birth rate and brisk immigration, the U.S. population exploded in the first half of the 19th century, from around 5 million people in 1800 to more than 23 million by 1850.
Such rapid growth—as well as two economic depressions in 1819 and 1839—would drive millions of Americans westward in search of new land and new opportunities.
President Thomas Jefferson kicked off the country’s westward expansion in 1803 with the Louisiana Purchase, which at some 828,000 square miles nearly doubled the size of the United States and stretched from the Mississippi River to the Rocky Mountains. In addition to sponsoring the western expedition of Lewis and Clark of 1805-07, Jefferson also set his sights on Spanish Florida, a process that was finally concluded in 1819 under President James Monroe.
But critics of that treaty faulted Monroe and his secretary of state, John Quincy Adams, for yielding to Spain what they considered legitimate claims on Texas, where many Americans continued to settle.
In 1823, Monroe invoked Manifest Destiny when he spoke before Congress to warn European nations not to interfere with America’s Westward expansion, threatening that any attempt by Europeans to colonize the “American continents” would be seen as an act of war. This policy of an American sphere of influence and of non-intervention in European affairs became known as the “Monroe Doctrine.” After 1870, it would be used as a rationale for U.S. intervention in Latin America.
Texas Independence
Cries for the “re-annexation” of Texas increased after Mexico, having won its independence from Spain, passed a law suspending U.S. immigration into Texas in 1830.
Nonetheless, there were still more Anglo settlers in Texas than Hispanic ones, and in 1836, after Texas won its own independence, its new leaders sought to join the United States. The administrations of both Andrew Jackson and Martin Van Buren resisted such calls, fearing both war with Mexico and opposition from Americans who believed calls for annexation were linked with the desire to expand slavery in the Southwest.
But John Tyler, who won the presidency in 1840, was determined to proceed with the annexation. An agreement concluded in April 1844 made Texas eligible for admission as a U.S. territory, and possibly later as one or more states.
Despite opposition to this agreement in Congress, the pro-annexation candidate James K. Polk won the 1844 election, and Tyler was able to push the bill through and sign it before he left office.
The Coining of 'Manifest Destiny'
By the time Texas was admitted to the Union as a state in December 1845, the idea that the United States must inevitably expand westward all the way to the Pacific Ocean had taken firm hold among people from different regions, classes and political persuasions.
The phrase “Manifest Destiny,” which emerged as the best-known expression of this mindset, first appeared in an editorial published in the July-August 1845 issue of The Democratic Review.
In it, the writer criticized the opposition that still lingered against the annexation of Texas, urging national unity on behalf of “the fulfillment of our manifest destiny to overspread the continent allotted by Providence for the free development of our yearly multiplying millions.”
As the phrase also appeared in a nearly identical context in a July 1845 article in the New York Morning News, its originator is believed to be John O’Sullivan, the editor of both the Democratic Review and the Morning News at the time. That December, another Morning News article mentioned “manifest destiny” in reference to the Oregon Territory, another new frontier over which the United States was eager to assert its dominion.
Oregon Territory
An 1842 treaty between Great Britain and the United States partially resolved the question of where to draw the Canadian border, but left open the question of the Oregon Territory, which stretched from the Pacific Coast to the Rocky Mountains over an area including what is now Oregon, Idaho, Washington State and most of British Columbia.
Polk, an ardent proponent of Manifest Destiny, had won election with the slogan “54˚ 40’ or fight!” (a reference to the potential northern boundary of Oregon as latitude 54˚ 40’) and called U.S. claims to Oregon “clear and unquestionable” in his inaugural address.
But as president, Polk wanted to get the issue resolved so the United States could move on to acquiring California from Mexico. In mid-1846, his administration agreed to a compromise whereby Oregon would be split along the 49th parallel, narrowly avoiding a crisis with Britain.
Impact of Manifest Destiny: The Civil War, Native American Wars
By the time the Oregon question was settled, the United States had entered into all-out war with Mexico, driven by the spirit of Manifest Destiny and territorial expansion.
The Treaty of Guadalupe Hidalgo, which ended the Mexican-American War in 1848, added an additional 525,000 square miles of U.S. territory, including all or parts of what is now California, Arizona, Colorado, New Mexico, Nevada, Utah and Wyoming.
Despite the lofty idealism of Manifest Destiny, the rapid territorial expansion over the first half of the 19th century resulted not only in war with Mexico, but in the dislocation and brutal mistreatment of Native American, Hispanic and other non-European occupants of the territories now being occupied by the United States.
U.S. expansion also fueled the growing debate over slavery, by raising the pressing question of whether new states being admitted to the Union would allow slavery or not—a conflict that would eventually lead to the Civil War.
Sources
Julius W. Pratt, “The Origin of ‘Manifest Destiny’,” The American Historical Review (July 1927).
Sean Wilentz, The Rise of American Democracy: Jefferson to Lincoln (New York: Norton, 2005).
Michael Golay, The Tide of Empire: America’s March to the Pacific
Era of U.S. Continental Expansion, History, Art & Archives: U.S House of Representatives.
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