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.