Mexican-American War

Mexican-American War, which is also referred to as the conflict between Mexico and the US, occurred from 1846 to 1848. It started after the US annexed Texas in 1845. Mexico considered the territory of Texas as its territory since General Antonio Lopez de Santa Anna signed a treaty with the US. 

Although the Republic of Texas was de facto independent, its citizens wanted to be annexed by the US. Due to its status as a slave state, Texas was not allowed to be annexed by the US. Both the US and Mexico sent soldiers to a disputed area. 

To try and negotiate the sale of the territory, President William Polk sent a diplomatic mission to Mexico. When the Mexican forces attacked the US forces, the war was declared. In 1845, the annexation of Texas was proposed, with Polk advocating for expansion through peaceful means or by armed force. 

There was also a disagreement between the two countries over who was the Rio Grande River.

his peace envoy, Nicholas Trist, of his post as a negotiator. But Trist successfully concluded the 1848 Treaty of Guadalupe Hidalgo. 

Some scholars see the Mexican–American War as leading to the American Civil War, with many officers trained at West Point, who saw action in Mexico, playing prominent leadership roles on each side. The question of how to treat the new acquisitions also intensified the debate over slavery in the United States. 

Since the war was fought on home ground, Mexico suffered a large loss of life for both its soldiers and its civilian population.

Beyond the disputed area of Texas, U.S. forces quickly occupied the regional capital of Santa Fe de Nuevo México along the upper Rio Grande, which had trade relations with the U.S. via the Santa Fe Trail between Missouri and New Mexico.

U.S. forces also moved against the province of Alta California and then moved south. The Pacific Squadron of the U.S. Navy blockaded the Pacific coast farther south in the lower Baja California Territory.

The Mexican government refused to be pressured into signing a peace treaty at this point, making the U.S. invasion of the Mexican heartland under Major General Winfield Scott and its capture of the capital Mexico City a strategy to force peace negotiations. Although Mexico was defeated on the battlefield, politically its government's negotiating a treaty remained a fraught issue, with some factions refusing to consider any recognition of its loss of territory.

Although Polk formally relieved his peace envoy, Nicholas Trist, of his post as a negotiator, Trist ignored the order and successfully concluded the 1848 Treaty of Guadalupe Hidalgo. 

It ended the war, and Mexico recognized the Mexican Cession, areas not part of disputed Texas but conquered by the U.S. Army. These were northern territories of Alta California and Santa Fe de Nuevo México.

The U.S. agreed to pay $15 million for the physical damage of the war and assumed $3.25 million of debt already owed by the Mexican government to U.S. citizens.

Mexico acknowledged the loss of what became the State of Texas and accepted the Rio Grande as its northern border with the United States. 

The victory and territorial expansion Polk envisioned inspired patriotism among some sections of the United States, but the war and treaty drew fierce criticism for the casualties, monetary cost, and heavy-handedness, particularly early on. 

The question of how to treat the new acquisitions also intensified the debate over slavery in the United States. Although the Wilmot Proviso that explicitly forbade the extension of slavery into conquered Mexican territory was not adopted by Congress, debates about it heightened sectional tensions.

Some scholars see the Mexican–American War as leading to the American Civil War, with many officers trained at West Point, who saw action in Mexico, playing prominent leadership roles on each side during the conflict. 

In Mexico, the war worsened domestic political turmoil. Since the war was fought on home ground, Mexico suffered a large loss of life of both its soldiers and its civilian population. The nation's financial foundations were undermined, the territory was lost, and national prestige left it in what a group of Mexican writers including Ramón Alcaraz and José María del Castillo Velasco called a "state of degradation and ruin.. [As for] the true origin of the war, it is sufficient to say that the insatiable ambition of the United States, favored by our weakness, caused it. U.S. forces occupied the regional capital of Santa Fe de Nuevo México along the upper Rio Grande. 

They also moved against the province of Alta California and then moved south. The Mexican government refused to be pressured into signing a peace treaty. Polk formally relieved