Carrillo was alcalde of Los Angeles in 1826, 1828, and 1833. In 1836, Juan Bandini, a prominent political official who supported the American cause, was back in the revolution-making business - this time in opposition to Governor Juan Bautista Alvarado. Carrillo returned from his post as territorial congressman in Mexico with the news that his brother, Carlos, had been appointed governor of Alta California to replace Alvarado, and that the capital had been changed from Monterey to Los Angeles.
During the Siege of Los Angeles, Carrillo, along with Captain José María Flores and Andrés Pico, formed a militia to defend Alta California during the Mexican–American War. Carrillo distinguished himself by leading fifty Californio Lancers to victory at the Battle of Dominguez Rancho against 203 United States Marines; killing 14, and wounding several others, while not suffering a single casualty. The Americans, under the command of US Navy Captain William Mervine, were forced to retreat from what is presently Carson to San Pedro Bay. Commodore Robert F. Stockton, leader of the US Pacific Naval Fleet, was so taken aback by the strong resistance of the Californios that he immediately set sail for San Diego to regroup. Two months later, Stockton rescued US Army General Stephen W. Kearny's surrounded forces after the Battle of San Pasqual, and with their combined, re-supplied force, they moved northward from San Diego, entering the Los Angeles area on January 8, 1847, linking up with John C. Frémont's Bear Flag battalion. With American forces totaling 660 soldiers and marines, they fought 150 Californios, led by José María Flores, with Carrillo second in command, in the Battle of Rio San Gabriel. The next day, January 9, 1847, they fought the Battle of La Mesa. On January 12, 1847, the last significant body of Californios surrendered to American forces. That marked the end of the war in California. On January 13, 1847, Carrillo, acting as a commissioner for Mexico, drafted in English and Spanish the Treaty of Cahuenga, and was present at the signing.
Reputation
"He was a man of remarkable natural abilities for the most part unimproved and wasted. Slight modifications in the conditions and his character might have made him the foremost in Californians - either the best or the worst. None excelled him in intrigue, and he was never without a plot on hand. A gambler, of loose habits, and utterly careless in his associations, he yet never lost the privilege of associating with the best or the power of winning their friendship. There was nothing he would not do to oblige a friend or get the better of a foe; and there were few of any note who were not at one time or another both his foes and friends. No Californian could drink so much brandy as he with so little effect. A man of fine appearance and iron constitution; of generous impulses, without much principle; one of the few original and prominent characters in early California annals."
