Mexican–American War: The Battle of Buena Vista: Five thousand American troops defeat 15,000 Mexican troops.

The Mexican–American War, also known in the United States as the Mexican War, was an invasion of Mexico by the United States Army. It followed the 1845 American annexation of Texas, which Mexico still considered its territory because it refused to recognize the Treaties of Velasco, signed by President Antonio López de Santa Anna after he was captured by the Texian Army during the 1836 Texas Revolution. The Republic of Texas was de facto an independent country, but most of its Anglo-American citizens who had moved from the United States to Texas after 1822 wanted to be annexed by the United States.

The Battle of Buena Vista, known as the Battle of La Angostura in Mexico, and sometimes as Battle of Buena Vista/La Angostura, was a battle of the Mexican–American War. It was fought between U.S. forces, largely volunteers, under General Zachary Taylor, and the much larger Mexican Army under General Antonio López de Santa Anna. It took place near Buena Vista, a village in the state of Coahuila, about 12 km (7.5 mi) south of Saltillo, Mexico. La Angostura was the local name for the site. The outcome of the battle was ambiguous, with both sides claiming victory. Santa Anna's forces withdrew with war trophies of cannons and flags and left the field to the surprised U.S. forces, who had expected there to be another day of hard fighting.

Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundaries with the Pacific Ocean to the west, the Caribbean Sea to the southeast, and the Gulf of Mexico to the east. Mexico covers 1,972,550 km², and is the thirteenth-largest country in the world by land area. With a population exceeding 130 million, Mexico is the tenth-most populous country in the world and is home to the largest number of native Spanish speakers. Mexico City is the capital and largest city, which ranks among the most populous metropolitan areas in the world.