Introduction Having recently completed a project of designing a set of rules for the Mexican- American War Santa Anna Rules!: Warfare in Mexico 1820-1870, available through Old Glory, I have read a number of books on the period in the past few months. When I began this project, I, like most Americans, was convinced that the war was an imperialistic land grab. As I read more and more books on the war, I became less convinced of this. In this article I will discuss the various causes for the war as I have compiled them from a number sources. In the space available, this article can be no more than a survey of the topic; however, I have included all my sources for the reader's further interest. Polk's Government Soon after his inauguration, Polk expanded on the Monroe doctrine by stating that the United States would oppose any new European colonies in the Americas. This eventually became known as the Polk doctrine and to some extent still remains in effect today. This doctrine was to guide Polk's administration. The Democratic platform on which President Polk campaigned asserted U.S. aims to annex Texas and U.S. claims to the Oregon territory. The Oregon territory included parts of what is now British Columbia, Oregon, Washington, Idaho, and part of Montana. Both the United States and Britain laid claim to this territory. Polk reiterated the U.S. claim to this territory in a speech to Congress on 2 December 1845. At the time of these claims, the United States and Britain did not enjoy over one hundred years of peaceful cooperation. In fact, just a few years earlier, 1812-1815, the United States and Britain had fought a war, sometimes referred to as the Second War of Independence. In February 1846, the United States rejected the British proposal for international arbitration. Neither country wanted war, and eventually the boundary was peacefully established on 15 June 1846. To resolve these two border disputes the Polk administration followed the same strategy of negotiation with both Mexico and Britain. The difference in outcomes was driven by the fact that Britain was willing and able to negotiate and the Mexican government was unable, even if at times willing, to negotiate. War of Texas Independence After the battle of San Jacinto, 21 April 1836, Texas won its independence from Mexico. Santa Anna was captured after the battle and forced to sign a treaty granting Texan independence. Since Santa Anna was the dictator of Mexico, this treaty was seen as legal by the eyes of most European nations. While the Mexican Congress almost at once repudiated the treaty, many countries, including the United States, Britain, and France recognized Texas as an independent nation. Only July 4th, 1845, a special session of the Congress of Texas voted for annexation to the United States. While the United States was making various overtures to Texas for annexation, the Mexican government more than once pronounced that the mere annexation of Texas would be considered an overt act of war. In fact, once Mexico learned that the United States had offered annexation to Mexico, the Mexican minister in Washington, Almonte, asked for his papers and returned home. This is a very important point to remember: the reason Mexico broke off relations with the United States was not the empty strip of land between the Nueces and Rio Grande but the annexation of Texas. Those who support the notion that the Mexican-American War was an imperialist crusade against a weaker neighbor often forget this. In fact at the time, most European military experts predicted an easy Mexican victory over the United States. Due to the impending threat of hostilities, as soon as the Texan government had approved annexation, General Taylor was issued orders to move his small army "on or near the Rio Grande." Disputed Texan Borders Initially, the United States claimed the Rio Grande as the boundary between the Louisiana territory and the areas held by Spain. In the treaty of 1819 with Spain, in which the United States purchased the Floridas, the United States and Spain set the boundary between the United States and Mexico at the Sabine River. When Texas was attempting to become an independent state in the Mexican Union, it asserted the boundary between Texas and Coahuila y Tejas as the Rio Grande. The Texas Declaration of Independence claimed the same boundary. The articles of surrender signed by General Filisola who succeeded Santa Anna after San Jacinto and his three division commanders also stipulated this boundary. The Mexican government repudiated this treaty, stating that it had been made merely in the name of Santa Anna. While Mexico refused to recognize Texan independence, they did not make any attempt to reassert their control over the territory. On 19 June 1844, Santa Anna notified the Texas government that he was resuming hostilities toward Texas, because they were negotiating with the United States over annexation, but still Mexico made no overt attempt to re-conquer Texas. By 1845, this border dispute had not been resolved. Once the United States annexed Texas, it inherited this border dispute. Mexican Politics and U.S. Overtures After Santa Anna's June 1844 pronouncement of the resumption of hostilities, he was driven from power and banished in December. As a result, a more pacific Herrera government came into power. In an effort to stave off war, Herrera was able to force a measure through the Mexican Congress, which offered Mexican recognition of Texas in exchange for a promise not to annex itself to the United States. The government of Texas unanimously rejected this measure, but the damage was done. For merely offering a peaceful solution to the problem, a number of Herrera's political enemies, including General Paredes, issued a number of pronouncements against Herrera. Pronouncements were the traditional means of beginning a revolution in Mexico. In the meantime, the Polk administration (having succeeded Tyler on March 4th, 1845) attempted to feel out the Herrera government. Since Almonte had left the United States, breaking off diplomatic relations, these feelers were sent through the British mission in Mexico City. The purpose of Polk's inquiries was to determine if Mexico would receive a representative from the United States to conduct negotiations. Through the Mexican Minister of Foreign Relations, Manuel de la Pena y Pena, the Polk administration was informed that such a representative would be received if the American fleet off Veracruz were withdrawn. Immediately Commodore Conner was ordered away from Veracruz and John Slidell was sent to Mexico as minister plenipotentiary, empowered to deal with all disputes between the two countries. When Slidell arrived in Mexico, the Herrera government began to backpedal. They stated that they were only prepared to receive a minister with limited powers to discuss only the subject of Texas. This limitation had never been discussed before, and Slidell's instructions from Polk did not include discussions of Texas' annexation. The United States maintained that Texas had been an independent nation, an independence maintained for ten years, and that neither Texas nor the United States needed Mexican permission for annexation. What then had Slidell come to discuss? The first issue was claims of American nationals against the Mexican government. Another issue was the boundary between the United States and Mexico. And finally, there was the status of California. For years claims by U.S. nationals against the Mexican government had been a source of dispute. In 1838, the United States accepted Mexico's offer to submit to arbitration. After two unsuccessful arbitration commissions, the King of Prussia offered his services at an arbitration commission in 1840. This commission found the Mexican government liable for $2 million in damages to be paid to the U.S. government in twenty quarterly installments. After the third payment, the Mexican government defaulted on its payments. The Polk administration sent Slidell with the offer for the U.S. government to assume the unpaid Mexican debt in exchange for the Rio Grande boundary. This was not without precedent, since a similar strategy had been used in connection with the Florida treaty with Spain. Polk also proposed a "better boundary" between the two nations: the Rio Grande to the Passo at 32 degrees latitude and then due West to the Pacific Ocean. This new boundary would cede to the United States the area known as Alta California. The United States was prepared to pay the Mexican government (badly in need of cash) up to $40 million for this territory. Since, however, Slidell was never accepted by the Mexican government, he was never able to present this proposal for the sale of Alta California; therefore, Polk's desire for California cannot be seen as a cause for war. In fact, Slidell's instructions clearly stated that he was not to let Polk's desire for California to impede his mission of peace. Remember that the United States was also involved in negotiations at the same time over the Oregon territory and the boundary between the United States and Britain. California was showing signs of wanting independence from Mexico, and the Polk administration was concerned that an independent California would be ripe for British annexation. In 1836 the population of California revolted against Mexico and established a new state government, one recognized by Mexican president Bustamante in 1838. When Santa Anna returned to power he sent troops to reassert Mexican control in California, but those troops too were driven out and the state government of California, under Pio Pico, recognized. This sparsely populated area, along with the coveted San Francisco Bay, was nearly a vacuum, and the United States feared that a European power would fill it. Because the Mexican government would not deal with Slidell on any of these issues, and because Slidell was not empowered to discuss the annexation of Texas, he was forced to depart. The fact that the Herrera government had even entertained the idea of admitting a commissioner from the United States was cause enough for General Paredes, commander at San Luis Potosi to pronounce against Herrera. Herrera fled the capital, and Paredes became president of Mexico in January 1846. Slidell was told by Polk to attempt to present his credentials to the new government. Clearly Paredes could not accept these credentials, since this was his main reason for pronouncing against Herrera. Paredes felt secure in his bellicose attitude toward the United States since he expected there to be war between it and Britain over the Oregon territory. First Blood On orders from Washington, Taylor moved his Army to the banks of the Rio Grande across from Matamoros, arriving in force on 28 March 1846. It must be remembered that Taylor was on ground claimed by the United States. The town of Matamoros was occupied by the forces of General de la Vega, who was subsequently superseded by General Ampudia and later General Arista, Because of de la Vega's hostile attitude, Taylor ordered the construction of Fort Texas on the U.S. side of the Rio Grande. When Arista assumed command, he brought with him orders from the Minister of War to attack Taylor's army. On 24 April, in accordance with these orders, Arista sent Torrejon and 1600 cavalry across the Rio Grande to cut off Taylor's lines of supply. In response, Taylor sent sixty-three dragoons, under Captain Thornton, to find the Mexican cavalry. Thornton's force was led into an ambush. Eleven men were killed and the rest wounded and/or captured. On 30 April, the main body of Arista's army crossed the Rio Grande. Soon afterward the battles of Palo Alto and Resaca de la Palmas were fought. All of these engagements were fought in the disputed area. Mexico had given warning to the United States that it considered annexation of Texas to be an act of war. The United States (and much of Europe) recognized the disputed area as part of Texas, and thus part of the United States. Entrance of Santa Anna and Peace Overtures Even During War Even after the battles on the Rio Grande between Taylor and Arista, the Polk administration still entertained hopes of avoiding war. In February 1846, Colonel Atocha approached the Polk administration with the suggestion that if Santa Anna were back in power in Mexico he would negotiate a peace settlement with the United States. In fact, a sum of $30 million was discussed for the purchase of the land desired by Polk. As a result, Polk had Secretary of the Navy Bancroft send a dispatch to Commodore Conner off Veracruz with instructions to allow any ship carrying Santa Anna to pass through the American blockade. When Santa Anna was allowed to return to Mexico, however, he seemed to have conveniently forgotten his promises to negotiate. Once back in power, he announced that he would follow the will of the people and that will was to defeat the invaders from the North. On 27 January 1846, Polk pursued another avenue toward peace. He had Secretary of State Buchanan send a message to the Mexican Foreign Minister stating that the United States would send a minister to Mexico or host a Mexican minister in the United States for purposes of negotiating a peace. Before this message reached Mexico, however, yet another government, that of General Salas ousted the Paredes government. The Salas government, on 31 August, sent a refusal to negotiate back to the United States. Polk was convinced that the Mexican goverment, short of cash, might agree to a peaceful settlement if the United States could offer $2 million advance settlement on such a bargain. To this aim, he had a bill introduced into Congress to provide such a sum for negotiations, Many Whigs who saw the annexation of Texas and (possibly) California as an attempt to extend slavery opposed this bill. The bill passed by a narrow majority in the Senate but was filibustered to death in the House of Representatives. So as hostilities grew and Taylor was marching southward into Mexico, Polk was denied on. of the tools he felt he needed to negotiate a peace. Salas was unwilling to negotiate in any event, and later Santa Anna seemed unable to negotiate. The two countries moved headlong toward a major war. Conclusion Despite popular misconception, the causes of the Mexican-American War are not black and white. It is clear that the United States knew that the annexation of Texas would provoke Mexico and that Polk desired that land of Alta California. It is not clear, however, that the Polk administration sought war. As war neared, there were a number of attempts made by the U.S. government to negotiate a peaceful settlement to the disputes, including the outright purchase of the disputed land. Polk and his advisors applied many of the same tactics that had worked in the past in border disputes with Britain, France, and Spain. In the case of Mexico, the realities of the internal political situation made negotiation unacceptable. Each government after Herrera dared not negotiate with the United States, or it would face overthrow. While the United States is often perceived as the aggressor in this conflict, the actions of the Mexican government may have driven the two countries into war. Sources Bauer, K. Jack. The Mexican War. 1846-1848. Lincoln, Nebraska: University of Nebraska Press, 1992. DePalo, William A. The Mexican National Army: 1822-1852. College Station, Texas: Texas A&M University Press, 1997. Eisenhower, John S.D. So Far From God - The US. War with Mexico, 1846-1848. New York: Doubleday, 1989. Henry, Robert Selph. The Story of the Mexican War. New York: Da Capo Press, 1950. Selby, John. The Eagle and the Serpent: The Invasions oj' Mexico: 1519 and 1846. New York: Hippocrene Books. Winders, Richard Bruce. Mr. Polk's Army: The American Military Experience in the Mexican War. College Station, Texas: Texas A&M University Press, 1997. (Editor's Note: Illustration above from Ulster Imports: From left to right: Texas Ranger, 1846; Officer US Infantry; Corporal US Infantry; US Cavalry; Mexican Spy Company; Illinois Volunteer. Thanks to Greg Novak.) Back to MWAN #92 Table of Contents Back to MWAN List of Issues Back to MagWeb Magazine List © Copyright 1998 Hal Thinglum This article appears in MagWeb (Magazine Web) on the Internet World Wide Web. Other military history articles and gaming articles are available at http://www.magweb.com