Today, May 13, 1846: U.S. Declares War with Mexico

After the formation of the United States and establishment of the original 13 states, America began to expand, mostly westward. Delaware was the first colony to officially become a state on December 7, 1787, followed shortly by Pennsylvania on December 12, 1787 and New Jersey on December 18, 1788. The last of the original 13 colonies to become a state was Rhode Island on May 29, 1790.

The first new states were Vermont (1791), Kentucky (1792) and Tennessee (1796). In 1800, America was a burgeoning nation of 16 states. By 1840, the nation had grown to 26 states with the last one being Michigan in 1837.

In 1836, Texas gained its independence from Mexico and became the Republic of Texas, its own nation. Some members of the US Congress began pushing for the annexation of Texas, but there was strong opposition from many of the northern states as they did not want to allow another slave state into the nation.

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In 1844, President John Tyler launched new negotiations with the Republic of Texas for the US annexation of the Lone Star nation with intent to make it a US state. A Treaty of Annexation was agreed to, but northern senators successfully defeated the idea, again because Texas would be another slave state.

Also in 1844, James K. Polk ran for President of the United States. His campaign was largely based on the idea of American expansion. He wanted to make Florida a state and spoke about taking the land from the Mississippi River west (Texas to California) to the Pacific coast and north to Oregon Territory. Polk won the election and was inaugurated on March 4, 1845 as the 11th president.

On March 1, 1945, just three days before his inauguration, Polk successfully negotiated a joint resolution in Congress to pass a Treaty of Resolution to allow Texas into the nation. They officially became the 28th state on December 29, 1845. This action was highly disputed by the Mexican government who still claimed Texas as part of their country.

Polk made an offer to Mexico for the land of New Mexico, which included Arizona, and California for a purchase price of up to $30 million, equivalent to around $937.5 million in 2015. The Mexican government refused the offer leaving Polk with the realization that obtaining the land he wanted could only be accomplished via conflict with Mexico. Subsequently, Polk sent General Zachary Taylor to the area of disputed ownership between the US and Mexico, located between the Rio Grande and Nueces Rivers in what is now the Mexican state of Coahuila.

On April 25, 1846, a Mexican cavalry attacked the US soldiers in the disputed area, killing around 12 of Taylor’s troops. Next the Mexicans laid siege against an American fort located along the Rio Grande. Calling in reinforcements, Taylor’s troops defeated the Mexicans at the battles of Resaca de la Palma and Palo Alto.

On May 11, 1846 with the news of the battles, Polk went to Congress and asked them for a declaration of war with Mexico. He told them the:

“…cup of forbearance has been exhausted, even before Mexico passed the boundary of the United States, invaded our territory, and shed American blood upon American soil.”

On this day, May 13, 1846, Congress granted Polk’s request and passed a declaration of war with Mexico, officially launching the Mexican-American War but not without some contention. Southern Democrats were supportive of the war, but northern Whigs were not. They saw it more as Polk’s land grabbing agenda and were not wanting to risk a war with Mexico to fulfill it. Whig opposition lasted after the war with Mexico was being waged.

In December 1946, the Whig opposition to Polk’s war was growing to the point that he accused them of treason.

In January 1947, the Whig controlled House voted 85 to 81 to censure Polk, declaring that he ‘unnecessarily and unconstitutionally’ started the war with Mexico. Leading the Whig opposition of Polk’s actions was the first term Representative from Illinois by the name of Abraham Lincoln. He went so far as to introduce 8 ‘spot resolutions’ in which he sought to establish or question the reason Polk gave for a declaration of war with Mexico. Lincoln called for the clarification to:

“Obtain a full knowledge of all the facts which go to establish whether the particular spot of soil on which the blood of our citizens was so shed was, or was not, our own soil at that time.”

The House never acted on Lincoln’s spot regulations and Polk continued to declare the conflict with Mexico as a just war. Kind of reminds me of some of our more recent wars or conflicts that have been called into question.

The Mexican-American War officially ended on February 2, 1848 when the US and Mexican officials signed the Treaty of Guadalupe Hidalgo. Among the terms of the treaty, Mexico officially recognized the US annexation of Texas. It also established the Rio Grande as the international border between the two nations, instead of the Nueces River as originally claimed by Polk. Upon signing the treaty, Mexico also agreed to sell New Mexico and California to the US for the price of $15 million, equivalent to about $454.5 million in 2015.

Thanks to Barack Obama’s open door and illegal immigration policies, Mexico is winning back California, Arizona, New Mexico and Texas at the expense of US taxpayers.


Sources for the above includes: Mexican-American War; President Polk declares war on Mexico; War (1846 – 1848); The Continent Divided: The U.S. – Mexico War; Mexican War; Mexican-American War; Inflation Calculator.


Dave Jolly

R.L. David Jolly holds a B.S. in Wildlife Biology and an M.S. in Biology – Population Genetics. He has worked in a number of fields, giving him a broad perspective on life, business, economics and politics. He is a very conservative Christian, husband, father and grandfather who cares deeply for his Savior, family and the future of our troubled nation.

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