Question

A question regarding the Mexican war.
What populations of non-Americans were left in the new territory acquired by the U.S.? What happened to them?

Answer 1

Answer:

The Mexican–American War, also known in the United States as the Mexican War and in Mexico as the Intervención Estadounidense en México (U.S. intervention in Mexico), was an armed conflict between the United States and Mexico from 1846 to 1848. It followed the 1845 U.S. annexation of Texas, which Mexico still considered Mexican territory since the government did not recognize the Velasco treaty signed by Mexican General Antonio López de Santa Anna when he was a prisoner of the Texian Army during the 1836 Texas Revolution. The Republic of Texas was de facto an independent country, but most of its citizens wished to be annexed by the United States. Domestic sectional politics in the U.S. were preventing annexation since Texas would have been a slave state, upsetting the balance of power between northern free states and southern slave states. In the 1844 United States presidential election, Democrat James K. Polk was elected on a platform of expanding U.S. territory in Oregon and Texas. Polk advocated expansion by either peaceful means or by armed force, with the 1845 annexation of Texas furthering that goal by peaceful means. For Mexico, this was a provocation, but Polk went further, sending U.S. Army troops to the area; he also sent a diplomatic mission to Mexico to try to negotiate the sale of territory. U.S. troops' presence was provocative and designed to lure Mexico into starting the conflict, putting the onus on Mexico and allowing Polk to argue to Congress that a declaration of war should be issued. Mexican forces attacked U.S. forces, and the United States Congress declared war.

Answer 2

The vast majority were victims of diseases such as dysentery, yellow fever, malaria and smallpox. According to scholar V.J. Cirillo, a higher percentage of U.S. troops died from sickness during the Mexican invasion than any war in American history. Manifest Destiny, a phrase coined in 1845, is the idea that the United States is destined—by God, its advocates believed—to expand its dominion and spread democracy and capitalism across the entire North American continent. The philosophy drove 19th-century U.S. territorial expansion and was used to justify the forced removal of Native Americans and other groups from their homes. The rapid expansion of the United States intensified the issue of slavery as new states were added to the Union, leading to the outbreak of the Civil War.