What happened in the April 25, 1846, clash between Mexican and U.S. troops?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

How the Mexican-American War changed the U.S. forever — Mexican-American War Learn how the Mexican-American War ultimately pushed the United States closer to civil war.

On April 25, 1846, Mexican troops crossed the Rio Grande and attacked forces under the command of U.S. General Zachary Taylor. This engagement resulted in 16 American soldiers being killed or injured.1

Following this event, U.S. President James K. Polk used the incident to justify a declaration of war. In his message to Congress on May 11, 1846, Polk asserted that Mexico had invaded U.S. territory and shed "American blood on American soil," a claim that served as the primary catalyst for the Mexican-American War.1