The annexation of Texas by the United States in 1845 was seen by Mexico as an act of aggression and led to the outbreak of war.

James K. Polk was the President of the United States from 1845 to 1849, during the Mexican-American War.

Zachary Taylor led the invasion of Mexico and won several key victories, including the Battle of Buena Vista.

Antonio López de Santa Anna was the President of Mexico during the Mexican-American War and led the defense of Mexico City.

As a result of the Mexican-American War, the United States annexed Texas, New Mexico, and California, Mexico ceded the Rio Grande as the border between the two countries, and the United States paid Mexico $15 million for the territories it acquired.

The Battle of Buena Vista, fought in February 1847, is considered the turning point of the Mexican-American War, as it marked the end of the Mexican army's offensive operations.

The Treaty of Guadalupe Hidalgo, signed in February 1848, ended the Mexican-American War and established the Rio Grande as the border between the United States and Mexico.

Approximately 13,283 American soldiers died in the Mexican-American War, mostly from disease.

It is estimated that around 25,000 Mexican soldiers died in the Mexican-American War.

As a result of the Mexican-American War, the United States acquired the states of Texas, California, New Mexico, and Arizona.

Winfield Scott led the American army that captured Mexico City in September 1847.

Major battles of the Mexican-American War took place in Mexico City, Puebla, Veracruz, and Monterrey.

David Farragut led the American naval force that captured Veracruz in March 1847.

John C. Frémont led the American force that invaded California in 1846.

Stephen W. Kearny led the American force that invaded New Mexico in 1846.