Why was the United States expansion in the early 20th century?

By 1820, the United States already extended well beyond its original boundaries. Through the Louisiana Purchase of 1803 and treaties with Spain and Britain, the nation's borders moved west to the Rocky Mountains, north to the 49th parallel, and south to Florida and the Gulf of Mexico. These boundaries remained essentially intact until the 1840s, when the United States acquired massive territories in the Southwest and on the Pacific Coast.

A complex mix of political, social, and economic factors fueled American expansionist sentiment in the 1840s. Many Americans subscribed to the concept of "Manifest Destiny," the belief that Providence preordained the United States to occupy as much land on the continent as possible. Some saw lucrative economic opportunities in the vast stretches of arable land and superb Pacific Coast ports. Others dreamed of the romance of settling uncharted terrain, or thought the United States should expand rapidly across the continent before foreign nations could do so. These expansionist yearnings fueled American settlement in Texas and Oregon, the acquisition of which became a principal object of American foreign policy by 1845.

Texas Independence

With the Adams-Onis Treaty of 1819, Spain settled a long dispute with the United States over its southern border. In return for Florida and the Gulf Coast lands east of the Mississippi River, the United States foreswore all claims to Texas in the west. However, soon after the treaty was in place the Mexican War of Independence ended Spanish rule on the continent and forced Spain to relinquish all rights to Texas.

The newly independent Mexican Republic rejected all American offers to buy Texas during the 1820s and 1830s, but agreed to grant huge tracts of inexpensive land to American settlers on the condition that they convert to Catholicism, learn to speak the Spanish language, and take Mexican citizenship. In response, more than three hundred slaveholding American families settled in Texas during the 1820s. Early settlers adapted well to their new home and met the conditions for settlement set by the Mexican government. But later, tensions arose between the Mexican government and the region's Anglo and Mexican settlers over the issues of slavery, taxation, and settlement requirements. The Mexican government responded by barring any further settlement in Texas by Americans and banning slavery.

Why was the United States expansion in the early 20th century?

Samuel Houston by Francis D'Avignon (c. 1814%#151;61), Lithograph on paper, 1848, NPG.93.270, National Portrait Gallery

The strained relationship between the Texans and the Mexican government turned violent in 1835 with the Texan Revolt. After a series of bloody engagements, including the legendary siege of the Alamo, the Texans, led by Sam Houston, won a decisive victory at San Jacinto in 1836. Following that battle, the Mexican army commander General Antonio López de Santa Anna signed, but later renounced, treaties that granted Texas independence and established its southwest boundary at the Río Grande.

While a majority of Texans and many Americans favored annexation in 1836, the admission of a slave-holding Texas (or several states formed from Texas territory) threatened the delicate balance of slave and free state representation in the Senate that had been carefully maintained since 1820. Rather than upset this balance, the United States recognized Texas as a sovereign nation, leaving the tensions between Mexico and Texas to simmer for the nine and one-half years of Texan independence.

Page 2

Far to the north and west of Texas, the United States and several other nations vied for the Oregon Country: the land north of California and west of the Rocky Mountains. The territory was variously claimed from the sixteenth century by Spain, Russia, Britain, and the United States. However, by the mid-1820s, only the American and British claims endured. The two nations agreed in 1818 to a "joint occupation" of Oregon in which citizens of both countries could settle; this arrangement lasted until 1846.
Why was the United States expansion in the early 20th century?

Map showing region claimed by both the United States and Britain until 1846, including Vancouver Island to the north.

The Oregon settlers from the United States and Britain were very different groups. The British were chiefly fur traders associated with the Hudson's Bay Company, while the Americans were a more eclectic lot. American settlement began in the 1830s when Protestant missionaries moved into the Wilamette Valley. Their accounts of the fertile soil of the region spread rapidly to the East and spurred a massive migration of thousands of American families westward along the Oregon Trail. The resulting population disparity along with an overall decline in the fur trade, convinced the British government to work for a negotiated settlement to the Oregon issue.

As with Texas, popular opinion over the Oregon Country was divided. Whereas Texas territory would have added proslavery representation in Congress, any potential states formed from the Oregon Country would be free states. Accordingly, Northerners were the chief advocates of acquiring as much Oregon Country as possible.

James K. Polk and the Policy of Expansion

In the presidential election of 1844, Democrat James K. Polk rode to victory over his Whig opponent Henry Clay on an aggressively expansionist platform that welded together the Texas and Oregon issues. Democrats appealed to the expansionist sentiments of both Northern and Southern voters and their shared desire to safeguard the sectional balance in Congress. After winning the election, Polk articulated his foreign policy goals: settlement of the Oregon dispute with Britain, annexation of Texas, and the acquisition of California from Mexico. The acquisition of California represented a significant expansion of American interest in Mexican territory and promised to complicate an already tense Mexican-American relationship over Texas.
Why was the United States expansion in the early 20th century?

Why was the United States expansion in the early 20th century?
James Knox Polk

Negotiated Settlement in Oregon

Negotiations between the United States and Britain over the Oregon Country began in the summer of 1845. The initial American proposal called for the boundary to be drawn at the 49th parallel, bisecting Vancouver Island. When British negotiators rejected this proposal, President Polk took a bolder position by reasserting his campaign promise to support the 54° 40' line and announcing the American intent to terminate the joint occupancy agreement within a year. While expansionist Northerners cheered these provocative actions with shouts of "Fifty-Four Forty or Fight!," Southerners in Congress made it clear that they would not risk war with Britain over Oregon.

British leaders were similarly adverse to conflict and did not want to jeopardize their important economic relationship with the United States. In June 1846, the Senate, preoccupied with war against Mexico, quickly approved the Oregon Treaty with Britain, setting the boundary at the 49th parallel.

Page 3

Relations between the United States and Mexico soured in December 1845, when Congress voted to admit Texas as the twenty-eighth state. A negotiated settlement to the Texas boundary question (now a disputed international boundary between the United States and Mexico) was complicated by frequent changes in Mexican leadership during 1845-46. After the Mexican government refused to meet with an American representative sent to negotiate the purchase of Mexican lands stretching northward from Texas to the Oregon Country in January 1846, Polk ordered U.S. troops into disputed territory on the north bank of the Río Grande. The inevitable conflict occurred on April 25, 1846, when a contingent of Mexican cavalry crossed the Río Grande and skirmished with the American forces.
Why was the United States expansion in the early 20th century?

 Map showing region claimed by both the United
States and Mexico until 1846.

During the nearly two years of war, American troops took possession of Mexican territory in what is now California, New Mexico, northern Mexico, and ultimately the capital, Mexico City. The Treaty of Guadalupe Hidalgo, which ended the war in February 1848, established dramatically altered boundaries for the United States and Mexico. Under the terms of Guadalupe Hidalgo, Mexico ceded to the United States an immense territory of nearly one million square miles, including land in what is now California, Nevada, Utah, New Mexico, Arizona, Colorado, Wyoming, Oklahoma, and Kansas. The United States, in turn, agreed to pay Mexico $15 million and assume $3.25 million in debt claims against Mexico. The treaty also provided that Mexican people who remained on their lands would be granted American citizenship and allowed to retain their property.

The Legacy of Expansion

By 1848, the Manifest Destiny championed by many Americans had been realized. The territory of the United States stretched from the Atlantic to the Pacific Coasts and from the 49th parallel to the Río Grande. Although they had been granted citizenship rights, many Mexican people who remained on their lands found the new American property laws complicated and confusing. Some unscrupulous American settlers used their greater familiarity with the law to acquire huge tracts of land owned by Mexicans.

The fertile territory acquired during 1840s also contained the bitter seeds of discord. Many Northerners and Southerners disagreed sharply over the slavery status of the territories, and eventually this dispute flamed into the carnage that was the Civil War. Today, the legacy of nineteenth century U.S. expansion is evident in the dynamic cultural and political interchange between the United States and Mexico. The people of each nation influence each other's language, food, music, and traditions, while their leaders continue to work together to resolve a host of political and environmental questions, including complex immigration, water rights, and land use issues.