Under the command of General Zachary Taylor, American forces advanced into the Mexican city of Monterrey following a series of battles during the Mexican-American War. Beginning in early September, the siege involved rigorous fighting as troops maneuvered through challenging terrain. Taylor’s army, comprised of around 6,600 men, faced formidable defenses from approximately 7,000 Mexican soldiers led by General Pedro de Ampudia.

The assault on Monterrey was marked by intense fighting, particularly during the battles at Molino del Rey and the Chapultepec Castle. As the siege progressed, American cannons pounded the city, and infantry assaults were launched. After days of fierce engagement, Taylor negotiated a surrender, securing control of Monterrey. The terms of surrender allowed Mexican forces to exit the city with their weapons, a move that generated contention among U.S. leadership and military strategists, questioning the efficacy of the war strategy.

This victory not only elevated Taylor's reputation, leading to his eventual nomination and election as President of the United States, but it also solidified American hold in northeastern Mexico. The capture of Monterrey was pivotal in the broader context of the war, influencing subsequent battles and the eventual outcome of territorial disputes between the two nations.