The newly-acquired territories of the Mexican cession set the stage for conflict between Northern and Southern interests to dominate them. In the case of the South, they observed the steadily increasing numbers of Northern immigrants flowing westward which threatened the political balance and harmony with the industrializing North. The bloody victory over Mexico was crowned with the black clouds of future warfare, and a dark legacy which remains with us today.
Bernhard Thuersam, www.Circa1865.com The Great American Political Divide
“Mexico Will Poison Us”
“Santa Anna had worked a prodigy: he had succeeded in raising a large army from a nation that was half in revolt against him, he had armed and equipped it, and he had made it a fine fighting force. It was a good army, it fought with sustained fury, it came exceedingly close to winning the two-day battle, and it might well have won it if Santa Anna’s own courage had lasted long enough to send it into action on the third day [at Buena Vista].
On the morning of the third day, instead of attacking again, he was already in retreat. The retreat became a panic, the army melted away, and it was only by what amounted to another miracle that he raised an army to oppose Scott.
It turned out a victory after all, a victory won by [Zachary] Taylor’s subordinates and the courage of the private soldier. But it was Captain [Braxton] Bragg and the other officers of artillery ((T.W. Sherman, George Thomas, John Reynolds), it was Jefferson Davis and the First Mississippi Rifles, above all it was the anonymous platoons, who won the battle.
Taylor may have inspired his troops: he certainly did not direct them. The company officers and the private soldiers improvised a rule of thumb defense on the spot as it was needed. The army was shot to pieces in two days of murderous fighting that was frequently hand-to-hand, but it was full of fight – and it held the field. Thus ended the military career of Zachary Taylor. His former son-in-law [Colonel Jefferson Davis] had won the election for him.
It was a little after noon of the second day when a brigade of Mexican cavalry, grandly uniformed, charged the one remaining strong point that defended a flank and protected the road to Saltillo by which an American retreat would have to move.
The troops of that strong point had been driven back and the Mississippi Rifles were coming up in support. Their wounded [Colonel Davis] formed them as a retracted flank, joining an Indiana regiment at a sharp angle. When the Mexican cavalry got within rifle range, it halted. Mississippi and Indiana blew it to pieces and there was no further attack in that part of the field.
By September Jefferson Davis was a Senator of the United States. In 1853 he was Secretary of War. In 1861 he was a President exercising the function of a military genius.
Winfield Scott, however, made an army and conquered a nation. He had, of course, brilliant assistants. [Daniel] Twiggs was a first rate fighting man, and William J.] Worth . . . was rather more than that. Moreover Scott had a handful of brilliant engineers – Robert E. Lee, who was effectively his chief of staff, [PGT] Beauregard, [George] Meade. Company and battalion officers whose names read like a list Civil War generals, North and South, fought in detail the campaign that Scott conceived and directed. The classic tactics of Robert E. Lee, the perfect battle of Chancellorsville, the converging attacks of Gettysburg, were all learned at the headquarters of Winfield Scott.
“The United States will conquer Mexico,” Ralph Waldo Emerson had said, “but it will be as a man swallows the arsenic which brings him down in turn. Mexico will poison us.”
(The Year of Decision: 1846; Bernard Devoto, Little, Brown and Company, 1943, excerpts, pp. 486-488; 492)