Manifest Destiny

The Whigs selected William Henry Harrison, a war hero from Tippecanoe, as their presidential candidate.
Harrison's running mate was John Tyler, a former Democrat who left the party due to disagreements with Andrew Jackson.
Slogan: "Tippecanoe and Tyler too!"
Harrison won the election but died 32 days into his presidency, marking the shortest term in U.S. history.

Tyler succeeded Harrison and encountered significant issues with the Whig Party, as he adhered to many Democratic principles.
Key conflicts arose due to Tyler vetoing initiatives like the National Bank and proposing to end the Independent Treasury System.
Major figures in the Whig Party, such as Henry Clay and Daniel Webster, opposed his actions, leading to the resignation of his entire cabinet.
Tyler's loss of party affiliation left him politically isolated, as neither the Whigs nor Democrats supported him.

Despite political struggles, Tyler attempted to annex Texas, a former republic recognized by Andrew Jackson.
This attempt faced resistance from Whigs, particularly against adding more slave states, leading to Tyler's failure in Congress.
By 1844, Tyler's presidency was largely viewed as a failure.

James K. Polk emerged as the Democratic candidate in the election of 1844, running against the established Henry Clay.
Polk advocated for the annexation of Texas as part of his campaign platform.
He won the election, succeeding Tyler and leading to the formal annexation of Texas in 1845.

Polk aimed to:
- Lower tariffs, contrasting with the Whig preference for higher tariffs.
- Promote the concept of Manifest Destiny, emphasizing expansion across the continent.
- Secure Oregon territory with the slogan "54-40 or Fight," claiming ownership from Britain.
Polk successfully negotiated the Oregon Treaty in 1846, establishing the U.S.-Canada border at the 49th parallel without conflict.

Manifest Destiny represented a belief that the U.S. was destined to expand across the continent from east to west.
This ideology often implied a sense of racial superiority, deeming indigenous and Mexican populations as uncivilized.
The term was first coined by John O'Sullivan in 1845, though westward expansion had been ongoing since colonial times.

Rising tensions between the U.S. and Mexico, particularly following Texas's annexation, led to conflict.
Polk sought to purchase California but was rebuffed by Mexico, prompting military action in disputed territories.
Following an attack on U.S. forces, the Mexican-American War began in April 1846 and lasted nearly two years.

The war faced significant opposition from Northerners, including Northern Whigs and Democrats, who viewed it as a move to expand slavery.
Abraham Lincoln introduced the Spot Resolution to challenge Polk’s claims regarding the war outbreak.
The Wilmot Proviso was proposed to ban slavery in territories acquired from Mexico, but it passed the House and failed the Senate.

The war concluded with the Treaty of Guadalupe Hidalgo, significantly changing U.S. territory.
The U.S. acquired California, New Mexico, and other regions, increasing its territory by one-third.
The treaty recognized the Rio Grande as the official U.S.-Mexico border and forced Mexico to relinquish claims to Texas.
This territorial gain intensified debate over slavery, re-entering it into national politics.

The administrations of Tyler and Polk demonstrate the growing tensions surrounding westward expansion and its repercussions on national politics, especially concerning slavery.
Understanding these events is crucial for grasping the causes leading up to the Civil War.