This President Was One Of The Mexican-American War's Harshest Critics

President Abraham Lincoln made a splash on the national political stage in 1847 with his opposition to the Mexican-American War. He was a first-term member of the United States House of Representatives when he began to speak out against the conflict, which had started the previous year (via History). The bitter fight between the United States and Mexico began as part of a land dispute.

After annexing Texas in 1845, the United States claimed that the new territory's border ended at the Rio Grande, while Mexico claimed that the Nueces River marked the end (via Britannica). President James K. Polk was also trying to negotiate to buy California and New Mexico, but Mexico rebuffed his offers. In response, Polk sent troops in to occupy the disputed land between the two rivers in January 1846 under the command of General Zachary Taylor. Late that April, Mexican troops attacked Taylor's soldiers in a skirmish that provided Polk with the ammunition needed to declare war. In a message to Congress, he said that Mexico "invaded our territory and shed the blood of our fellow-citizens on our own soil" (via the Miller Center).

Abraham Lincoln, then a young representative from Illinois, began his one and only term in the House of Representatives in March 1847 (via U.S. House of Representatives). He questioned the motivations behind the Mexican-American War and claimed that Polk sought "military glory — that attractive rainbow that rises in showers of blood" (via Politico).

Lincoln also wondered whether the war had really started on the American side of the border. In December 1847, the congressman presented eight motions known as the Spot Resolutions to the House. He wanted to "obtain a full knowledge of all the facts which go to establish whether the particular spot on which the blood of citizens was so shed was or was not at that time our soil" (via the Council on Foreign Relations).

Lincoln's opposition to the war didn't play with the press or his constituents back in Illinois. According to The New Republic, one Illinois newspaper called him "the Benedict Arnold of our district," and there were local protests as well. Yet while Congress didn't act on Lincoln's Spot Resolutions, it did rebuke Polk the following year for "a war unnecessarily and unconstitutionally begun by the President of the United States" (via The Washington Post). The Mexican American War ultimately ended in February 1848 with the Treaty of Guadalupe Hidalgo, which brought more territory into the United States, including what is now New Mexico and California. Lincoln left the House in 1849 without seeking reelection and remained out of public office until he was elected president in 1860.