Mexican War: Future Civil War Commanders

Figure 1.--Here is one of the many Civil War figures who served in the Civil War. This 1846 Daguerreotyoe portatit shows newly commissioned Brevet Second Lieutenant George B. McClellan in uniform fresh out of West Point posing with his father and brother before shipping out for the Mexican-American War.

The Mexican War was a major factor in the outbreak of the Civil War. It had secured vast Western lands that Southern Planters wanted to expand slavery. Cotton could not be grown in the northern states formed from the Louisiana Purchase. Cotton could be grown in Texas and the states to be formed in the southwest could provide new slave states to balance out the increasing majority of Free states. Many planters also understood the need for western land because of the degree to which intense cotton cultivation reduced the fertility of the soil. The Mexican War thus undermined the Missouri Compromise which had deescalated sectional discord. The growing anti-slavery forces, including young Congessman Abragam Lincoln, recognized this and opposerd the War. The Mexican War is also notable because of the roles played by key figures in the coming American Civil War. Many of the senior figures of the Civil War fought in the Mexican War. It was in Mexico that they got their first taste of combat. Much of what they knew about war was learned in Mexico. It was the Mexican War provided these career officers with vital combat experience -- something which can not be learned at a West Point classroom. Some of the Confederates included: Braxton Bragg, P.G.T. Beauregard, Jefferson Davis, Henry Heth, Thomas Jackson, Joseph Johnston, Robert Lee, James Longstreet, and George Pickett. Federal officers included: Ulysses Grant, Winfield Scott Hancock, George McClellan, George Meade. William Tecumseh Sherman, and George Thomas. Notably Ambrose Burnside arrived in Mexico fer the fighting. Most of these men served in minor roles as junior officers. This was not the case of Lee. He was an engineer on Winfield Scott’s staff, becoming part of Scott’s inner circle of officers which became his 'little cabinet'. Scott significantly influenced Lee and much of his command style came out of his relationship with Scott who at the onset of the Civil War commanded the U.S. Army and authored the war-winning Anaconda Plan. One source explains Scott's imprint on Lee. "Scott taught Lee how to command an army in addition to teaching him important tactics and strategies. In Mexico, Lee learned that superior numbers did not guarantee a victory, that one could win with smaller forces by using superior tactics which included creative use of the terrain, surprise, flexibility, and adaptability. Lee took these lessons to heart during the Civil War as he won numerous victories despite inferior manpower by creating a tactical advantage. Scott believed risk-taking was the best way to maximize an advantage. While Scott did not like to throw his troops into battle haphazardly, he preferred offense to defense. Lee matched Scott's boldness and became a very aggressive and calculated general." What Lee did not learn was the imprtance of industry in backing military operations, at least before the ar began. Lee admired and respected Scott, not only during the Mexican War, but throughout his career. Scott was convinced that there would not be a civil war. It seems likely that this influenced Lee's decision to side with Virginia and the Confederacy. That of course is speculation. What is not speculation is that most of the many of the Civil War's most effective commanders were the commanders who had fought in Mexico. Grant was more of a junior officer in Mexico and had liitle contact with Taylor a virtually no contact with Scott. Lincoln who despite having almost no military experperience became one of the three great war preidents in American history. Davis in contrast with substantial war experience was a failure.

Created: 5:20 AM 10/3/2006
Last updated: 7:13 PM 11/8/2025