In the Battle of Monterrey (September 21–24, 1846) during the Mexican–American War, General Pedro de Ampudia and the Mexican Army of the North was defeated by the Army of Occupation, a force of United States Regulars, Volunteers and Texas Rangers under the command of General Zachary Taylor. The hard-fought urban combat led to heavy casualties on both sides. The battle ended with both sides negotiating a two-month armistice and the Mexican forces being allowed to make an orderly evacuation in return for the surrender of the city. Wikipedia

Not to be confused with the Battle of Monterey; Early on 7 July 1846, the frigate USS Savannah and the two sloops, USS Cyane and USS Levant of the United States Navy, captured Monterey and raised the flag of the United States. The only shots fired were a 21-gun salute to the new U.S. flag fired by each of the U.S. Navy ships in the harbor. Wikipedia

From: GUEST,Vince Date: 21 Oct 21 - 01:37 PM Santa Anna did actually win the day at Angostura or Buena Vista as the Yankees called it. He fought Taylor to a standstill and, his army being re-assembled on the following day, had he again attacked would have smashed to U.S. ranks. Instead, much to the annoyance of his troops, he withdrew to face the threat imposed by Scott's landing at Vera Cruz.

Library of Congress www.loc.gov tells a different story; Battle of Buena Vista
United States General Zachary Taylor was victorious over Mexican General Antonio Lopez de Santa Anna in the Battle of Buena Vista on February 23, 1847. Named for a nearby hacienda, the Battle of Buena Vista was fought near Monterrey in northern Mexico. On the evening of February 21, General Taylor received a message from General Santa Anna offering to accept an American surrender and be spared the battle. Taylor reportedly replied: “I decline accepting your request.” For the next two days, the Mexican army of over 15,000 troops assaulted the smaller U.S. force of only 5,000 men. The agile field artillery and advantageous battle position, however, favored General Taylor against overwhelming odds. By nightfall of February 23, the exhausted and dispirited Mexican army retreated; Taylor elected not to pursue the troops and remained to secure the region.

General Winfield Scott landed at Veracruz in March and headed west toward Mexico City. At the Battle of Cerro Gordo in April, he defeated the Mexican army; Santa Anna again escaped capture. Despite strong resistance, Scott pressed forward and captured the Mexican capital in September, securing U.S. victory in the Mexican American War.

Taylor’s victories at the Battle of Buena Vista and the 1846 Battle of Palo Alto and Resaca de la Palma, won him national fame that contributed greatly to his election as president in 1848. Scott, too, ran for president but was defeated in 1852 by another veteran of the Mexican American War, Franklin Pierce.

Warfare History Network The Battle of Buena Vista
Although Santa Anna displayed the artillery pieces O’Brien had lost at Buena Vista and falsely claimed that his troops had won a victory, seven months later soldiers of the U.S. Army would march victoriously through the plaza of Mexico City. In August, during the Battle of Padierna, the two lost guns were recaptured by the 4th U.S. Artillery. Transferred to the U.S. Military Academy at West Point, they were placed on exhibit beneath a plaque reading simply, “Lost without dishonor, recovered with glory.”