Abraham Lincoln’s involvement with Mexico dates back to the 1840s when he introduced the controversial “Spot Resolutions”.
In May, 1846, President James Polk reported to Congress that Mexico had invaded U.S. territory, and that “blood was shed on American soil”, so they declared war. Many in the opposition Whig Party felt Polk’s provocative aggression was a way to expand slavery and many Americans doubted his claims of invasion.
Las “Resoluciones del Sitio” (PDF)
A few months later, Abraham Lincoln was elected to Congress from Illinois as a Whig. In December, 1847, he burst onto the national scene when he introduced eight resolutions demanding evidence of the exact “spot” on which American blood was shed.
While Congress never voted on Lincoln’s “Spot Resolutions”, the House approved an amendment in January, 1848, stating that the war with Mexico was launched “unnecessarily and unconstitutionally”.
Partly due to his opposition to the Mexican War, Lincoln lost his House seat in 1848. In the process, though, he forced a national debate, became well-known, and endeared himself to many people in Mexico.
The “Spot Resolutions”
Whereas the President of the United States, in his message of May 11, 1846, has declared that "the Mexican Government not only refused to receive him, [the envoy of the United States,] or listen to his propositions, but, after a long-continued series of menaces, has at last invaded our territory and shed the blood of our fellow-citizens on our own soil:"
And again, in his message of December 8, 1846, that "we had ample cause of war against Mexico long before the breaking out of hostilities; but even then we forbore to take redress into our own hands until Mexico herself became the aggressor, by invading our soil in hostile array, and shedding the blood of our citizens:" And yet again, in his message of December 7, 1847, that "the Mexican Government refused even to hear the terms of adjustment which he [our minister of peace] was authorized to propose, and finally, under wholly unjustifiable pretexts, involved the two countries in war, by invading the territory of the State of Texas, striking the first blow, and shedding the blood of our citizens on our own soil."
And whereas this House is desirous to obtain a full knowledge of all the facts which go to establish whether the particular spot on which the blood of our citizens was so shed was or was not at that time our own soil: Therefore, Resolved By the House of Representatives, That the President of the United States be respectfully requested to inform this House --
1st. Whether the spot on which the blood of our citizens was shed, as in his messages declared, was or was not within the territory of Spain, at least after the treaty of 1819, until the Mexican revolution.
2d. Whether that spot is or is not within the territory which was wrested from Spain by the revolutionary Government of Mexico.
3d. Whether that spot is or is not within a settlement of people, which settlement has existed ever since long before the Texas revolution, and until its inhabitants fled before the approach of the United States army.
4th. Whether that settlement is or is not isolated from any and all other settlements by the Gulf and the Rio Grande on the south and west, and by wide uninhabited regions on the north and east.
5th. Whether the people of that settlement, or a majority of them, or any of them, have ever submitted themselves to the government or laws of Texas or the United States, by consent or compulsion, either by accepting office, or voting at elections, or paying tax, or serving on juries, or having process served upon them, or in any other way.
6th. Whether the people of that settlement did or did not flee from the approach of the United States army, leaving unprotected their homes and their growing crops, before the blood was shed, as in the messages stated; and whether the first blood, so shed, was or was not shed within the enclosure of one of the people who had thus fled from it.
7th. Whether our citizens, whose blood was shed, as in his message declared, were or were not, at that time, armed officers and soldiers, sent into that settlement by the military order of the President, through the Secretary of War.
8th. Whether the military force of the United States was or was not sent into that settlement after General Taylor had more than once intimated to the War Department that, in his opinion, no such movement was necessary to the defence or protection of Texas.