Question

You have been reading about the war between the United States and Mexico from 1846 to 1848. It sprang out of a dispute between two countries over the southern border of Texas. The U.S. claimed the Rio Grande as the border, while Mexico claimed the Nueves River farther north. Each based its claim, in part, on agreements made at the end of the Texas war for independence, which ended in 1836. Each also based its claim on nationalism, or national self-interest, and a desire to expand its territory. For this portfolio project, you will explore different perspectives regarding the Mexican-American War. You will then present your findings in a short essay. Your final product will describe each point of view. It should give historically accurate facts.

can you do a 5 paragraph essay in which i can reference to and get an idea on what to write? also, i do not think the war was justified.

Answer 1

The Mexican–American War (1846–1848) grew out of a disputed southern border for the independent Republic of Texas and broader U.S. ambitions for territorial expansion. After Texas won independence in 1836, the Texan government and the United States maintained that the Rio Grande marked Texas’s southern boundary; Mexico insisted the border was the Nueces River farther north, and it never fully recognized Texan independence. When the United States annexed Texas in 1845 and President James K. Polk pushed to acquire California and New Mexico, the disagreement over the border escalated into military confrontation. In this essay I will present the main perspectives—those of expansionist Americans and the Polk administration, the Mexican government and people, and Americans who opposed the war—and explain why, in my view, the war was not justified.

Supporters of the war in the United States framed the conflict as a legitimate defense of American territory and an expression of “Manifest Destiny,” the widely held belief that the United States was destined to expand across the continent. After annexation, the U.S. moved troops under General Zachary Taylor to the Rio Grande; when Mexican cavalry engaged a U.S. patrol in the Thornton Affair (April 1846), President Polk told Congress that “American blood has been shed on American soil” and asked for a declaration of war. Expansionists—including many Democrats in Congress and southern politicians who hoped new land would provide room for slavery—argued that taking control of California and the Southwest was both strategically valuable and consistent with national destiny. They saw the conflict as a straightforward enforcement of American claims and a chance to secure continental influence.

From the Mexican perspective the American actions looked like aggression and a violation of sovereignty. Mexico had experienced political instability after Texas’s 1836 revolt and regarded the Treaties of Velasco—signed by General Santa Anna under duress—as invalid, so it refused to accept the Rio Grande border. Mexican leaders and ordinary citizens viewed U.S. troop movements across territory Mexico considered its own as an invasion rather than a defense. Mexico lost large swaths of territory in the war and in the Treaty of Guadalupe Hidalgo (February 2, 1848), which set the Rio Grande as Texas’s border and ceded the vast Mexican Cession (present-day California, Nevada, Utah, and parts of Arizona, New Mexico, Colorado and Wyoming) to the United States for $15 million plus the U.S. assumption of certain claims. For Mexico, the war was a national tragedy that cost land, lives, and international prestige.

Many Americans opposed the war for legal, moral, and political reasons. Prominent Whigs and anti-expansionists argued that President Polk had manufactured or exaggerated the border incident to provoke hostilities. Abraham Lincoln, then a young Whig congressman, introduced the “Spot Resolutions,” demanding that Polk identify the exact spot where blood was shed to prove it was on U.S. soil; Henry David Thoreau refused to pay taxes in protest and wrote “Civil Disobedience.” Abolitionists and many northerners denounced the war as a scheme to extend slavery into new territories—evidence later surfaced in debates such as the Wilmot Proviso (1846), which sought to ban slavery in any territory gained from Mexico. Domestic opposition emphasized that the war raised constitutional and ethical problems and that it needlessly sacrificed lives for sectional and expansionist aims.

Weighing these perspectives, the war appears unjustified. The legal basis for immediate U.S. military action was weak: Mexico disputed Texas’s status and its southern border, and the Treaties of Velasco were contested. Polk’s administration pushed an ambitious territorial program and used a border encounter to gain public and congressional support for war—actions that look more like calculated expansionism than unavoidable defense. The human cost was high, Mexico lost vast territory and sovereignty, and the new lands intensified sectional conflict in the United States, hastening debates that contributed to the Civil War. Given the disputed claims, the diplomatic alternatives that were available, and the evident political motives to expand slavery and power, the Mexican–American War cannot be justified as a necessary or honorable act of self-defense.

Sources you can consult for further detail: primary documents such as Polk’s war message to Congress (May 1846), Abraham Lincoln’s Spot Resolutions, and the Treaty of Guadalupe Hidalgo (Feb. 1848), as well as secondary works on Manifest Destiny and the Mexican perspective. These will give you direct material to cite if you need to expand this into a longer paper.