Contents[show] Preliminaries Prior to the Mexican-American War the Californio forces had already driven the Mexican appointed Governor Manuel Micheltorena and most … The Battle of Monterey, at Monterey, California (sometimes confused with the Battle of Monterrey, in Nuevo León, Mexico), was waged on July 7, 1846, during the Mexican-American War. The Battle of Monterey, at Monterey, California, occurred on 7 July 1846, during the Mexican–American War. The action made the ongoing Bear Flag Revolt superfluous. The so-called Battle of Monterey, at Monterey, California, was waged on July 7, 1846, during the Mexican-American War. The United States captured the town unopposed. The Battle of Monterey . The United States captured the town unopposed.