The Mexican War, 1846–1848

Mexican-American War (1846-1848)

The Great Territorial Loss

From the perspective of the United States, the Mexican-American War, together with the Louisiana Purchase, represented important land acquisitions as part of the country's relentless expansion westward. In this regard, Kurth (1999) reports that, "There were grand achievements in this national project of continental expansion, especially the southwestern annexations, which were achieved through U.S. military victory in the Mexican-American War. In this case, the United States took advantage of the fact that Britain and France were disrupted by serious internal turmoil."

With Britain and France otherwise occupied with their more immediate domestic issues, the U.S. was free to pursue its expansionist Manifest Destiny plans for the Western regions of the country, including most especially California and its vast resources and temperate weather.

From the perspective of the Mexicans, though, the invasion by the United States was a heavy-handed blow by an international bully that had provoked a war just to acquire land. The U.S. invasion of Mexico in 1846 resulted in the 1848 Treaty of Guadalupe Hidalgo that secured an enormous amount of territory from Mexico, including Texas, New Mexico, and California, for the United States.

Not surprisingly, this humiliating defeat has been the source of longstanding bitterness against the United States by Mexico. The Mexican -- American War that was fought between the United States and Mexico is described by Reiter as being "a semi-exclusionary, moderately repressive regime fighting a long losing war."

Following Mexico's loss to the United States, Mexican president Antonio Lopez Santa Anna fled to Venezuela in exile.

The exiled president's end, though, was not as ignominious as the act indicates. In this regard, Reiter reports that, "Santa Anna resigned the presidency voluntarily, he did so while the war was ongoing (September 1847), and even after he resigned as president he kept his position as leader of Mexico's army."

Although the new Mexican president, Manuel Pena y Pena (who was appointed by Santa Anna) eventually relieved Santa Anna of his commander in chief position, and took refuge in Venezuela to avoid the impending court martial.

The Issue of Slavery

Having acquired enormous territories in the West by virtue of the peace treaty signed with Mexico following the end of the Mexican-American War in 1848, the status of these new territories became the focus of debate between Southern and Northern states concerning the issue of slavery. According to Huston, "Southerners demanded the privilege of taking slavery into the new territories if the environment permitted profitable undertakings; Northerners wanted slavery absolutely and explicitly excluded from them."

Although comprising a single purportedly united country, the Northern and Southern states were at two extremes in terms of their economies and views about slavery. Following the end of the Mexican War, the United States was larger in geographic size, but the country had added all of this new territory during a period in its history when states' rights about slavery were at the forefront of debate. Increased sectionalism inextricably expanded slavery into these territories and the proviso offered by David Wilmot in 1846 that would restrict slavery to its then existing boundaries was intended to allow the country to develop "normally" under this onerous status quo.

The fundamental issues that were involved, though, did not readily lend themselves to such a straightforward solution. In this regard, Huston emphasizes that, "Northerners often did not react like Lincoln in seeing a demise of slavery by some natural mechanism; instead, they pictured a more complicated scenario."

Conversely, the overarching issues that were involved from the perspective of slave-owning states were more pragmatic and immediate. According to Huston, "Most important, southerners, though exhibiting some confusion in their predictions, believed that limiting slavery to its existing boundaries would produce poverty, depopulation of whites, and ultimately race war."

Clearly, the South's perspective was overwhelmingly economic in nature but political in tone while the North's perspective was political in nature but economic in effect. With so much at stake, it is little wonder that two such divergent perspectives emerged in response to the Wilmot Proviso in 1846. In this regard, Huston emphasizes that, "In their search for an understanding of what the future might bring under the Wilmot prohibition, southerners were misled by classical economic theory; and thus they read into the Wilmot Proviso a more grim outcome than was likely."

Although history provides 20-20 hindsight, it appears that few observers at the time could have predicted the unintentional impact that the Wilmot Proviso would have on America's historical course. As Huston concludes, "By this route, by leading southerners to miscalculate the effects of a prohibition against slavery's geographical expansion, Malthusian population theory, and classical political economy in general, helped push the South to secession and the nation to civil war."

The Popular Sovereignty proposal to allow voters to decide on slavery within their territories resulted in the Compromise of 1850 and finally achieved the immediate goals of the Wilmot Proviso.

Critics of popular sovereignty argued that its provisions were too weak and failed to guarantee slaveholder access to the territories.

Nevertheless, the Compromise of 1850 bought the country a few more years of troubled peace. In this regard, Huston reports that, "In state conventions in late 1850 and in the congressional and gubernatorial elections; of 1851, those who accepted the Compromise of 1850 -- dramatically triumphed. At least for a few years, the sectional issue of slavery in the territories slumbered."