President James Polk hoped to use diplomatic means to persuade Mexico to allow Texas to join the Union. He offered to buy large areas of land - what are now California and New Mexico - and thereby enrich the Mexican government, which was hoping to create a roadblock to Texas’s statehood by disputing the exact location of Texas’s southern border.
The Mexican government, already hoping to stop Texas from becoming one of the United States, was in no mood to sell other pieces of land to the U.S., even if such a deal meant millions of dollars for Mexico. As historians Allan R. Millett and Peter Maslowski write,
The question of Texas’s southern boundary aggravated the annexation issue. Texas claimed the Rio Grande, but Mexico insisted the Nueces River was the border. Accepting the Texans’ interpretation, Polk ordered Brigadier General Zachary Taylor to assume a position “on or near” the Rio Grande. Taylor stopped at Corpus Christi at the mouth of the Nueces, which was neither on nor very near the Rio Grande, but Polk acquiesced. However, on January 12, 1846, Polk learned his special envoy had failed to persuade Mexico to accept the Rio Grande boundary and to sell New Mexico and California. The next day he ordered Taylor to the Rio Grande. By late March the general’s Army of Occupation had concentrated opposite Matamoros. From Polk’s perspective Taylor had assumed a forward defensive position; the Mexicans considered Taylor’s advance an invasion.
While Zachary Taylor was maneuvering on Mexico’s northern border, diplomatic relations between the United States and Mexico went from bad to worse. Finally, gunfire erupted between groups of soldiers when the Mexican ambushed two of Taylor’s squadrons. Then actual battles took place. Finally, on May 13, Congress declared war on Mexico.
While the initial fighting took place on that northern border, General Winfield Scott was preparing for a landing and invasion into Mexico from the southeast. This would be a major amphibious operation, as Brion McClanahan writes:
Scott was sixty when the Mexican War began in 1846. His young man’s dreams of military glory had long departed; because of his age, Scott preferred that younger men take the reigns of battle in Mexico. But fate would intervene. Scott was sent to Mexico by President James K. Polk and commanded the southern arm of the two field armies. In 1847 he invaded Mexico at Veracruz - the first large-scale amphibious assault in American history, surpassed only by Operation Overlord (D-Day) in 1944. He punished the Mexican army and pushed quickly toward Mexico City. Scott was aided by the outstanding leadership of several subordinates, among them Robert E. Lee - Scott called him the finest soldier he had ever seen - and Thomas J. Jackson. Scott captured Mexico City within five months of landing on the Mexico beaches. He had become the conqueror of Mexico and a household name in the United States.
In addition to Robert E. Lee, other officers sent to Mexico were Ulysses S. Grant, Jefferson Davis, and James Longstreet. Action in Mexico was thus a common threat, fifteen years later, among officers on both sides of the Civil War. Winfield Scott was by that time too old to be on active duty, but did function as a military advisor to President Lincoln. Zachary Taylor would die shortly after the war with Mexico and long before the Civil war.
Zachary Taylor would gain attention as a hero of the war, and subsequently elected president. Winfield Scott, however, may have been the better commander of the two, but got less attention in the newspapers of the day.
Winfield Scott, while not receiving the type of media attention which would get him into the White House, was still popular among ordinary citizens of the United States. He fit into, and simultaneously helped to shape, the concept of an American military hero. He was victorious, and yet scrupulous in his regard for human life. He was brilliant in his strategy and tactics, yet clear in his consideration for the rights and dignity of the inhabitants of the territories he conquered. Winfield Scott typifies what is most admirable in the American military tradition, and in the military tradition of Western Civilization: a frank acknowledgement that, while the evils of war are necessary, the evils of war also should be minimized. As historian Russell Frank Weigley writes,
Winfield Scott’s greatest campaign, from Veracruz to the halls of the Montezumas in the Mexican War, permitted him to wage limited war in the pre-Napoleonic, eighteenth-century style most congenial to him. He conducted the campaign with strict regard for the rights of the citizens of the invaded territories, with every effort to confine bloodshed and suffering to the enemy’s armed forces and to avoid inflicting them upon civilians. He imposed stringent regulations to compel orderly conduct from his soldiers in their dealings with the Mexican populace and to confine the opportunities for friction to the minimum necessary for the sustenance of his army and the morale of his troops. He forbade forced requisitions and insisted upon the purchase of supplies, this despite a most precarious logistical situation at the end of a long supply line across the Gulf of Mexico and through the yellow-fever belt of the Mexican coast. After he landed near Veracruz, he eschewed the sort of costly assault which his colleague Zachary Taylor had recently employed in similar circumstances to take the fortified city of Monterrey, preferring instead to save lives through a formal siege of the eighteenth-century style (with the ironic result that because Scott’s casualties at Veracruz were low, the American public inclined to believe that Taylor’s capture of the weaker defenses of Monterrey was a greater achievement; after all, the price was higher). Throughout his campaign, Scott avoided all-out battle whenever it was possible to do so and husbanded lives by substituting maneuver for combat with all the frugality of a general of the ancien regime.
Without detracting from the accomplishments of either Taylor or Scott, historian Irving Levinson offers a slightly different perspective on the war. It is all too easy to frame the narrative of a war as a struggle between two monolithic nation-states, and ignore the internal tensions within those states, and the effects of those tensions on the war. Levinson details the different segments of Mexican society, and how each had a slightly different stance vis-a-vis the war:
I contend that an additional force of Mexicans played a critical and heretofore unknown role. As the U.S. Army advanced towards Mexico City, the repeated destruction of Mexican military formations deprived Mexico’s repressive regime of the most important tool by which that nation’s rulers secured their dominant economic and political positions. Consequently and concurrently, a broadly based rebellion led by disenfranchised rural Mexicans erupted and soon posed so great a menace to the existing social order that those who ruled Mexico sought first peace and then aid from the United States to crush this uprising. In this new perspective, Mexico stands as a society whose distinct history and resulting characteristics defined the types of action open to both governments during the war. With that said, a brief description of the realities of the nation in which almost all of the fighting took place stands as our first task.
Although the war with Mexico was smaller, by various metrics, than other wars in United States history, it was significant. It gave us a president in Taylor, a presidential hopeful in Scott, a series of officers who would shape the Civil War, a clear example of the American ethic of humane treatment of civilians in wartime, and geographical boundaries which shape North America two centuries later.