MEXICAN WAR, The. The annexation of Texas in 1845 laid the foundation for the war with Mexico. Although Texas had been for many years practically free, and had been recognized by the United States, England, France and other countries,. yet Mexico still re fused to acknowledge its independence. When therefore the United States proposed to admit Texas into the Union, Mexico gave warning that the annexation would be equivalent to a declaration of war, and 6 March 1845 protested, and soon afterward withdrew her Minister and severed diplomatic relations. Her acts, how ever, scarcely justified her threats, as at that time at least little or no preparation was made for war. It has, therefore, been claimed that had the American government used a concilia tory policy peace might have been preserved, and friendly relations re-established.
At the moment, however, the Mexican peo ple and authorities were in a rather belligerent attitude, due in part to pride, and in part to an expectation that the United States would soon be involved in a war with Great Britain over the Oregon boundary, in which case Mexico would have a powerful ally to aid her. Did President Polk at this point seek to strengthen this hope in the minds of the Mexicans, in tending at the proper moment to make a com promise and peace with England, as was done, and thus leave Mexico at the mercy of the United States? Perhaps history can never answer the question, but events at least seemed to march in harmony with the thought. For Mexico soon found herself in the dilemma that she must either sell California to the United States, receiving in return a goodly sum of money to appease her pride, or engage in a war i to sustain her honor and territorial integrity. Mexico bravely, but perhaps not wisely, chose the latter alternative, not fully realizing the inequality of the contestants, nor the depth of the humiliation to which she would be subjected. Doubtless President Polk preferred to acquire California without war; but its acquisition was to be the principal measure of his administra tion. Hence if war was the only means to secure it, war it must be; at least enough to get possession of the desired territory.
Causes of the The immediate occa sion, however, of the war was the dispute in regard to the western boundary of Texas. Proclaiming her independence in 1836 Texas asserted that her western boundary was the Rio Grande to its source, thence due north to the 42d degree of north latitude. The following
year the United States recognized her inde pendence, and in December 1845, by a joint resolution, admitted her into the Union as a State, providing that boundary disputes were to be settled by the United States. President Polk accepted the boundary line claimed by Texas, and 13 Tan. 1846 ordered Gen. Zachary Taylor to march to the eastern bank of the Rio Grande as the western boundary of the United States. Mexico insisted that the Nueces River — 100 miles eastward — was the true western boundary of Texas, and therefore that General Taylor was now on Mexican soil. On 25 April 1846, the first blood was shed in a conflict be tween a band of Mexican troops that had crossed to the eastern side of the Rio Grande and a company of American soldiers. The news of this action was immediately com municated by General Taylor to President Polk, who sent his now noted message to Congress, asserting that war was begun by the act of Mexico on American soil. Congress accepted, after a stormy debate in the Senate, the Presi dent's 'statement, and war was recognized as existing.
Other causes than the two already noted were also at work, and help to make a decision in regard to the justness of the war still more difficult. Mexico for many years had been in a chronic state of revolution. The natural re sult followed. American citizens in Mexico sustained property losses and doubtless were frequently unjustly arrested and even impris oned. Claims arising from these causes had been in part settled under a convention of 1840; but many of them were still pending. Some were just; more, either unjust or extravagant in amount. President Polk united these unset tled claims with the boundary question, and de manded that Mexico receive an envoy extraor dinary with power to settle both — on its face an eminently fair proposition. On the other hand, Mexico professed to be ready to receive an ambassador to settle the boundary dispute, but declined to receive Mr. Slidell as our minis ter when commissioned to settle all disputes, insisting that the two questions were distinct in kind and origin and should not be united. President Polk in his message asserted that this action of Mexico was in violation of her promise to receive a minister, and hence justi fied his administration in its measures, and forced him to take possession of the disputed territory.