Manifest Destiny

29c. "American Blood on American Soil"

James K. Polk
White House
President James K. Polk was not favored to win his party's nomination to the presidency, but his expansionist views were favored by the American people.

While Polk awaited the Presidency, the trouble of Texas resurfaced.

Congress admitted Texas to the Union in a joint resolution passed the day before Polk's inauguration. Mexico was outraged. Inclusion in the United States would forever rule out the possibility of re-acquiring the lost province.

Furthermore, the boundary was in dispute. Mexico claimed that the southern boundary of Texas was the Nueces River, the Texan boundary while under Mexican rule. Americans, as well as the incoming President, claimed that the boundary of Texas was the Rio Grande River. The territory between the two rivers was the subject of angry bickering between the two nations. Soon it would serve as the catalyst for an all-out war.

President Polk's true goal was to acquire the rich ports of California. He envisioned a lucrative trade with the Far East that would revolve around San Francisco and Monterey. Great Britain also had designs on the territory, so Polk thought he would have to act fast. He sent John Slidell to Mexico with an offer. The United States would pay Mexico a combined sum of $30 million for the Texan boundary of the Rio Grande, New Mexico territory, and California.

Disputed Territory
The disputed territory along the Texas-Mexico border is shaded above. The boundary along the right is the Nueces River (the border which Mexico recognized) and the one along the right is the Rio Grande (which was recognized by the United States).

The Mexican government was livid. They were not interested in selling the valuable territory. Instead they issued the highest diplomatic rebuke. They refused even to receive Slidell to hear his offer. The American President was enraged. He resolved to fight Mexico.

In July of 1845, Polk ordered General Zachary Taylor to cross the Nueces River with his command of 4,000 troops. Upon learning of Slidell's rejection, Polk sent word that Taylor should advance his troops to the Rio Grande River. From the standpoint of Mexico, the United States had invaded their territory. Polk hoped to defend the disputed area with armed force. He also knew that any attack on American troops might provide the impetus Congress was lacking to declare war.

Mexican-American War

Was Polk justified in ordering Taylor to cross the Nueces River?



Sure enough, in May of 1846, Polk received word that the Mexican army had indeed fired on Taylor's soldiers. Polk appeared before Congress on May 11 and declared that Mexico had invaded the United States and had "shed American blood on American soil!" Anti-expansionist Whigs had been hoping to avoid conflict, but news of the "attack" was too much to overlook. Congress passed a war declaration by an overwhelming majority. President Polk had his war.

On the Web
Heritage Gateways: Mormon Pioneer Trail
When the Republic of Texas was admitted to the Union as a state, all of present-day southwestern U.S., including Utah, belonged to Mexico. Nevertheless, Mormon leaders began planning a great migration of Mormons to Great Salt Lake City. Beginning in February 1846, the migration continued for over 20 years bringing more than 100,000 settlers to the region. This mega-website celebrates the journey of these pioneers. Browse or use the search tool to find specific details of pioneer life on the trail.
Inaugural Address of President James Polk
President James Polk's inauguration followed rapidly on the heels of Texas' admission to the Union. Polk's inaugural address, which is provided in full at this website, discusses at length the new state of Texas and territorial expansion.
James Knox Polk
The website of James Polk's ancestral home in Columbia, Tennessee, has posted a two-part biography of the President, the first covering his early career and the second covering the election of 1844 and his Presidency. Very nicely illustrated.
James Polk's request to Congress, May 11, 1846
On May 11, 1846, President James Polk updated Congress on recent events concerning Texas. The emissary he sent to Mexico with an offer of cash in exchange for disputed lands was rudely rebuffed. Then, Mexicans opened fire on Americans at the Rio Grande River, killing 16. "War exists," Polk declared. This webpage offers the full text of his address.
Narrative History of Texas Annexation, Secession, and Readmission to the Union
The Texas State Library and Archives Commission provides a comprehensive look at Texas and statehood from the first vote of Texans in 1836 in support of annexation, the successful push through Congress, secession from the Union in 1861, and, finally, to readmission as a state, with links to relevant documents.

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