The origins of the Mexican War are far more complex than usually presented in modern textbooks, with England figuring prominently into the reasons behind a hurried annexation. A need to preserve Texas as a reliable supplier of cotton, while limiting American expansionism, propelled Britain into mediating Mexican-Texan difficulties. While New Englanders opposed annexation on supposedly moral grounds, they coveted California which would give them a port more convenient for whaling and their opium traffic with India – the latter creating severe addiction problems in China.
John C. Calhoun opposed James Polk’s war with Mexico with a plea “that America never take one foot of territory by an aggressive war.” He added, “If fight we must, let us fight a defensive war.” He dismissed Polk’s assertion of “war exists with Mexico” as a “palpable falsehood.”
The Fatal Precedent
“The way Polk got the [Mexican] war started ensured that it would be vehemently protested in certain quarters. Shortly after Texas was annexed (December 29, 1845), Polk ordered General Zachary Taylor, commander of the army in Louisiana, to move to Texas to protect its southern flank on the Rio Grande.
In reality, the southern flank was the Neuces, 150 miles to the north; Mexico claimed the area between the two rivers, and the pretensions of Texas and the United States was without foundation. An American reconnoitering party of sixty-three men encountered a Mexican force near the Rio Grande and was attacked. Eleven were killed, five wounded and the rest captured.
When Polk received the news, he asked Congress to appropriate funds to support Taylor, declared that the Mexicans had invaded the United States and “shed American blood on the American soil,” and requested not a declaration of war but a recognition that “war exists” by virtue of Mexico’s action.
The Democratic majority in the House limited debate to two hours, read but a few of the documents Polk had submitted, and passed a bill calling for volunteers and appropriating $10 million. Just sixteen congressmen voted against the bill.
Among the few in Congress who spoke against the action was John C. Calhoun. Unlike northern opponents of the war, he had strongly favored the annexation of Texas, but he thought the war was avoidable, set a dangerous precedent . . . The passage of the appropriations bill with its “war exists” preamble in effect transferred to the presidency Congress’s power to declare war, for the president as commander in chief could order troops anywhere, provoke a fight, and present Congress with was a fait accompli.
The precedent could prove fatal, Calhoun insisted, for it “will enable all future presidents to bring about a state of things, in which Congress shall be forced, without deliberation or reflection, to declare war, however opposed to its convictions of justice or expediency. The precedent would, indeed, be applied to Calhoun’s own State fifteen years later.”
(States’ Rights and the Union: Imperium in Imperio, Forrest MacDonald, University of Kansas Pres, 2000, excerpts pp. 150-151)