The Mexican-American War had a significant impact on the United States and Mexico. The war was primarily a territorial dispute caused by the United States' policy of manifest destiny. President Polk and the American citizens wanted to expand their nation by acquiring all of the land on the North American continent regardless of the native people already residing on the land. Some southerners wished to acquire more slave states in order to strengthen slavery as an institution. In addition, the United States wished to obtain the Pacific ports and natural resources in the Mexican territories. However, by focusing only on the struggle between the two nations, individuals often disregard the indigenous people residing in the disputed territories. As a result of the war, the Tejanos, Nuevo Mexicanos, and Californianos lost their homeland. Since neither nation would accept these individuals as full citizens, they were forced to assimilate into either culture by essentially erasing their own traditions. In this way they became second-class citizens. Therefore, the Mexican-American War was certainly unjust. Both nations, especially Mexico, endured hardships following the two year war.
There were positive and negative effects on the United States following the Mexican-American War. The war was the first time the United States fought on foreign territory and occupied another nation's capital. The Treaty of Guadalupe Hidalgo granted the United States half a million miles of territory which lead to the discovery of gold and silver in California and significantly contributed to the national economy and westward expansion.
However, the war further divided the United States between slave owners and abolitionists. The new territories disturbed the balance of power between free and slave states. In addition, the Americans suffered an additional 11,000 casualties after the war from disease alone. Finally, the financial cost of the war was about 75 million dollars. In contrast to the United States, Mexico suffered more severely from the war. The government was forced to enact a conscription, which resulted in the deaths of many peasants; there were more than 25,000 military and civilian casualties. Additionally, since the war was fought on Mexican territory, many buildings, roads, and ports were destroyed. The Treaty of Guadalupe Hidalgo created an artificial political border, which inadvertently divided families. The Mexicans residing in the former Mexican territories were forced to assimilate into American culture and were regarded as inferior individuals by the United States. The war resulted in political and economic chaos as well. Mexico experienced many different Presidents during the war; however, the federal republic was finally re-established in 1847. The draft weakened the national agrarian economy since most farmers were required to serve in the war. During the war, the daily paper, "El Republicano" stated, "No one had any doubts about the intentions the Washington cabinet has had now for some time with respect to Mexico...One fights in the name of usurpation; the other defends justice...A government that starts a war without a legitimate motive is responsible for all its evils and horrors. The bloodshed, the grief of families, the pillaging, the destruction, the violence, and its works and its crimes...such is the case the U.S. Government, for having initiated the unjust war it is waging against us today." As a result of all the suffering the war caused the nation, Mexicans often refer to the war as the "American Intervention."
