History 103: US History I

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Throughout the first half of the 19th century, the United States expanded its borders all the way to the Pacific Ocean, fulfilling its manifest destiny. Find out about the reasons people wanted this land, the path that took them there and the politicians who supported it all.

Westward Expansion

In 1840, North America was home to three republics, two monarchies and dozens of distinct Native American nations. Within less than a decade, most of it would belong to the United States.

Americans had been trying to expand throughout all of the nation's history - pushing beyond Jamestown, plowing the frontier of Pennsylvania. Then they wanted to cross the Proclamation Line, and of course, go into the Louisiana Territory. After the War of 1812, they turned their attention to Oregon.

In the late 18th and early 19th centuries, both the British and Americans explored and claimed territory in the Pacific Northwest, an area that came to be known to Americans as the Oregon Country. After the 1818 Rush-Bagot Treaty reached a joint occupancy agreement, thousands of settlers crossed overland to the new territory. Stretching 2,000 miles from Missouri to the Pacific Coast, the Oregon Trail was blazed by fur trappers like John Jacob Astor as a footpath. But within a couple of decades, the wagon trail included bridges and mountain passes, taking nearly half a million people not just to Oregon but to many 'jumping-off points,' leading prospectors to California, Mormon refugees to Utah and settlers anywhere there was fertile land, displacing thousands of Native Americans in the process.

It wasn't long before many Americans began calling for the total annexation of Oregon - and other territory, as well. In 1845, journalist John O'Sullivan defended America's claim on the territory, saying, '…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.' A lot of people agreed with him.

Executive Expansionists

John Quincy Adams was one of America's first and most ardent advocates for expansion. Back in 1811, he had written to his father, former President John Adams, 'The whole continent of North America appears to be destined by Divine Providence to be peopled by one nation, speaking one language, professing one general system of religious and political principles, and accustomed to one general tenor of social usages and customs.'

Adams went beyond the idea of mere expansion; his goal was called continentalism because he intended that the United States would not just occupy the lands void of European settlers but encompass all of North America. President James Monroe worked to achieve these ends, securing America's border with Canada at the Rocky Mountains and with Mexico at the Pacific Ocean. He established the Rush-Bagot Treaty, he purchased Florida and he wrote the Monroe Doctrine.

Reasons for Expansion

Why the push to take over the continent? There were a lot of different reasons. Clearly, some people believed that extending America's borders from coast to coast was both a God-given purpose (or destiny) and it was obvious and inevitable (in other words, manifest). Some saw expansion as a matter of national defense - they were concerned about increased British or Mexican influence in North America. Others wanted to occupy as much territory in North America as possible for economic reasons and secure ports to Asia on the West Coast. Some wanted to expand the reach and influence of slavery into new places.

Another motive was land. A baby boom plus dramatic increases in immigration more than quadrupled the population between the turn of the century and 1850, and all those people needed somewhere to go. Then economic downturns occurred in both 1818 and 1839. The frontier offered people a second chance with new opportunities in business and cheap (or even free) land. Land ownership represented freedom, wealth and political power. And new technology such as steam power and the telegraph made the prospect of moving westward a little less intimidating. About 4,000,000 people (more than the population of the 13 colonies during the Revolution) moved west between 1820 and 1850.

Achieving Manifest Destiny

At first, many people envisioned manifest destiny as a romanticized ideal: white Americans would move in to desirable land and set up perfect societies that would soon petition for annexation into the US. Of course, America could negotiate for more territory or buy it outright. War was another option. Regardless of the process, many politicians adopted the phrase 'manifest destiny,' and O'Sullivan's words came to symbolize America's driving national purpose for half a century. Today, his phrase also represents an era in US history.

Some expansionists didn't want to wait for the US government to achieve manifest destiny. Unauthorized soldiers known as filibusters or freebooters carried out private military expeditions to secure land. The infamous William Walker attempted to colonize parts of Mexico and Nicaragua. He was on his way to victory until he infuriated American millionaire Cornelius Vanderbilt, who convinced the US navy to destroy his regime. Undeterred, Walker went into Honduras just six months later. This time, he made the British navy angry, and they oversaw his execution.

With many options on the table for achieving it, manifest destiny became unofficial government policy in the 19th century as America was faced with the need, the desire and the opportunity to take more land. In the West, politicians saw everything they needed to expand the prosperity of America's growing population: land, markets, ports. In the 1840s, President James Polk negotiated with Britain for most of the Oregon Territory and set the United States on a course to control the land from sea to shining sea. And it didn't really matter who was in the way.

Lesson Summary

Let's review. Since its founding, America had been spreading out. Starting in 1818, American settlers set their sights on the Oregon Territory. Half a million people followed the Oregon Trail to the Pacific Ocean and many jumping-off points along the way. Though the Rush-Bagot Treaty stipulated joint occupancy, many Americans wanted the United States to annex the Oregon Territory. In defense of this idea, journalist John O'Sullivan said that America had a manifest destiny to overspread the continent, but it was far from a new concept. John Quincy Adams and James Monroe both believed in this goal, and much of the population agreed. But the people had many different motives for expansion and many different ideas about how to achieve it. William Walker tried to do it himself! By mid-century, the presidents were using all means available to spread American influence from coast to coast.