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the Readings


Inquiry Question

Historical Context


Reading 1
Reading 3



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Determining the Facts

Reading 2: The Army of the West

The mid-1840s was a period of intense expansionism in the United States. Many Americans succumbed to the view that the country's "manifest destiny" was "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."1 The principal obstacles to these ambitious plans were Mexico's northern provinces.

Texas had declared its independence in 1836 and successfully defended that independence at the decisive Battle of San Jacinto. The Republic of Texas, settled largely by Southerners, immediately requested admission to the United States as a slave state. Rather than risking war with Mexico and reopening the divisive question of the expansion of slavery into the territories, the government in Washington turned down the request. By 1844, ardent expansionist James Polk had been elected president on a platform calling for the annexation of Texas. In early 1845, Congress narrowly approved a joint resolution annexing Texas, which was then admitted to the Union as the 28th state.

Hoping to add Mexico's Pacific Coast ports to the United States, Polk sought first to purchase the Mexican provinces of New Mexico and California. When Mexico refused his offer, he sent American troops into an area along the Rio Grande in Texas claimed by both the U.S. and Mexico and waited. On April 25, 1846, Mexican forces tried to remove what they saw as intruders on Mexican soil. The resulting skirmish ended with the death of 11 Americans. On the basis of the shedding of "American blood on American soil," Polk declared that the U.S. and Mexico were at war.

American forces moved quickly into Mexican territory. In the summer of 1846, Stephen Watts Kearny and his 1,600-man Army of the West marched out of Fort Leavenworth, on the Missouri River, in the direction of New Mexico. Kearny elected to follow the tortuous older route of the Santa Fe Trail through the Raton Mountains. He chose the Mountain Branch for two reasons. Bent's Fort, a fortified trading post close to the Mexican border, offered a convenient base of operations, and more water was available on the Mountain Branch than on the notoriously dry Cimarron Desert in the middle of the summer. Kearny set out from Bent's Fort on August 2, followed by a train of wagons. Road crews went ahead to improve the trail through Raton Pass as best they could. The army crossed in one day with great difficulty. In many places they were forced to use ropes to raise the wagons over rocks. In the descent, the narrow trail wreaked havoc, and many wagons were destroyed.

Kearny expected armed opposition from Manuel Armijo, the provincial governor. Two thousand men were supposed to be entrenched in Apache Canyon, a narrow passage at the west end of Glorieta Pass. American traders in Santa Fe apparently convinced Armijo that resistance was useless. When Kearny's army arrived, Apache Canyon was deserted. One of Kearny's men commented that "had Armijo's heart been as stout as the wall of rock which nature gave him to aid in defense of his country, we might have sought in vain to force this passage."2

Kearny captured Santa Fe without a struggle and proclaimed the annexation of New Mexico. The Army of the West moved on to California. A brief rebellion that killed the newly appointed governor and other Americans in Taos was quickly put down. New Mexico, which included the present state of Arizona, continued under military rule until 1851, when it gained territorial status as part of the Compromise of 1850.

By 1848, the U.S. Army had occupied Mexico City and the Mexican War was over. In the Treaty of Guadalupe-Hidalgo, Mexico ceded to the United States more than 900,000 square miles. The American government paid $15 million in exchange and agreed to take over all claims by American citizens against Mexico. Five years later, Mexico agreed to sell the United States an additional strip of land along the Gila River for $10 million. With the Gadsden Purchase, the present-day boundaries of the United States were complete, but the fierce debates about the War and about the possible extension of slavery into the new territories had sharpened sectional antagonisms that threatened to tear the country apart.

Questions for Reading 2

1. What were the causes of the Mexican War?

2. Why did Gen. Kearny decide to travel through Raton Pass?

3. What did Kearny expect in Apache Canyon? What actually happened?

4. What effect did the territorial expansion resulting from the war have on the United States?

Reading 2 was adapted from Richard Greenwood, "Raton Pass" (Las Animas County, Colorado, and Colfax County, New Mexico) National Historic Landmark Nomination Form, Washington, D.C.: U.S. Department of the Interior, National Park Service, 1975; and William E. Brown, The Santa Fe Trail: National Park Service 1963 Historic Sites Survey (St. Louis, MO: The Patrice Press, 1988).

1 John L. O'Sullivan, New York Morning News, Dec. 7, 1845; cited in Ray Allen Billington, The Far Western Frontier: 1830-1860 (1956; reprint, New York: Harper and Row reprint edition, 1962), 149.
2 Frank S. Edwards, A Campaign in New Mexico with Colonel Doniphan (Philadelphia, 1847), 44-45; cited in Billington, The Far West Frontier, 180.


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