Manifest Destiny, Slavery, and the Breakdown of the Union

"Manifest Destiny" is a phrase that expressed the belief that the United States had a divinely inspired mission to expand, spreading its form of democracy and freedom.The phrase "Manifest Destiny" was first used primarily by Jackson Democrats in the 1840s to promote the annexation of much of what is now the Western United States (the Oregon Territory, the Texas Annexation, and the Mexican Cession). Slavery, the exploitation of Africans for hard labor, was also growing vastly in popularity during this period of territorial expansion. These controversial ideologies, including such events as Mexican War, the Wilmont Provisio, the development of the Republican Party, the Dred Scott Decision, the Brooks-Sumner Incident, the Anthony Burns Incident, the Ostend Manifesto, Uncle Tom's Cabin, and unbalanced congressional representation aided in sending the Union into uproar and eventually splitting it entirely.

The Mexican War between the United States and Mexico began with a Mexican attack on American troops along the southern border of Texas on Apr.

Aqueduct City of Mexico

An animation showing when United States territorie...

Mexican Cession in Mexican View

25, 1846. Fighting ended when U.S. Gen. Winfield Scott occupied Mexico City on Sept. 14, 1847; a few months later a peace treaty was signed at Guadalupe Hidalgo. In addition to recognizing the U.S. annexation of Texas, defeated Mexico ceded California and , New Mexico (including all the present-day states of the Southwest) to the United States. During the war political quarrels arose regarding the disposition of conquered Mexico. A strong "All-Mexico" movement urged annexation of the entire territory. Abolitionists opposed that position and fought for the exclusion of slavery from any territory absorbed by the United States. In 1847 the House of Representatives passed the Wilmot Proviso, stipulating that none of the territory acquired should be open to slavery. The Senate avoided the issue, and a late attempt to add it to the Treaty of Guadalupe...