Jack Powers (c. 1827 – October 26, 1860), whose real name was John A. Power, was an Irish-born American outlaw who emigrated to New York as a child and later served as a volunteer soldier in the Mexican–American War in the garrison of Santa Barbara, California. During the California Gold Rush, he was a well-known professional gambler and a famed horseman in the gold camps as well as in San Francisco, Santa Barbara and Los Angeles.

Powers had two brushes with the law. He was tried as a member of The Hounds in San Francisco in 1849, and was also involved in a dispute over the ownership of a ranch in Santa Barbara County in 1853. In 1856, at Santa Barbara, Powers protected a fugitive from the vigilantes of San Francisco and helped him escape. When his role was revealed the following year, he was harassed by vigilantes in Los Angeles, who accused him of being the leader of a criminal gang there. Long known for his skills as a horseman, on May 2, 1858, he set a record-breaking time in a 150-mile race. Soon after this race, he was accused by San Luis Obispo vigilantes of complicity in the 1857 murder of two men, and of being the head of a notorious bandit gang that plagued the southern central coastal region of California along the El Camino Real, with robberies and murders in San Luis Obispo County and Santa Barbara County between 1853 and 1858. This gang was later named the Jack Powers Gang in 1883, by Jesse D. Mason in his History of Santa Barbara County California. Mason, Jesse D; History of Santa Barbara County, California, with illustrations and biographical sketches of its prominent men and pioneers, Thompson & West, Oakland, Cal., 1883, Chap. XVI, XIX

Escaping the vigilantes by fleeing to Sonora, Powers attempted to return to California in 1860, but was murdered and robbed by his vaqueros at Calabasas just inside the Arizona Territory.

Jack Powers was described at the time of the May 1858 long-distance race in the Daily Alta California as being "a spare built man, with full sunburnt face, heavy hair and whiskers, and a keen eye."

Early life Born in Ireland in 1827 as John A. Power, he came to the United States with his parents in 1836, and settled with them in New York City. John was 19 years of age when the Mexican–American War commenced in 1846, and he and his older brother Edward joined Company G of the 1st Regiment of New York Volunteers with many of his friends from New York. His brother was made a corporal. His brother-in-law, Charles Heffernan, enlisted in Company F, accompanied by his wife, John's sister. The New York Volunteers was a unit organized by Colonel Jonathan D. Stevenson to occupy and settle California, and men in the unit were promised land in the region should the war be successful.Santa Barbara History Makers, Tompkins, 1983, p. 103–104Baker, p. 42

Early years in California In San Francisco, Power and his brother transferred to Company F under Captain Francis J. Lippitt, one of three companies of the 1st New York Volunteers which were then sent to Santa Barbara, California. The two other companies were soon sent to occupy towns in the southern part of Baja California Territory, where they saw some action before the end of the war. Power and his company remained in Santa Barbara as a garrison, in relative idleness until the disbanding of the regiment in September 1848, just a few months after the beginning of the California Gold Rush.

Power remained in the town as a gambler until late in the year, when he left for the mines with his brother-in-law in a party of other men of his regiment. William A. Streeter and William Henry Ellison, Recollections of Historical Events in California, 1843–1878 (Concluded), California Historical Society Quarterly, Vol. 18, No. 3 (Sep., 1939), pp. 254-278, University of California Press in association with the California Historical Society One of those men, James Lynch, later wrote an account of that journey to the goldfields and of their return to San Francisco for the winter of 1848 in his 1882 book, With Stevenson to California, 1846–1848.James Lynch, Francis Clark, The New York Volunteers in California, The Rio Grande Press, Inc., Glorietta, NM, 1970.

When Power returned to San Francisco for the winter, he became a gambler there and also became associated with the San Francisco Society of Regulators. He was subsequently accused of being a member of the notorious anti-immigrant criminal gang "The Hounds" by a popular vigilante movement organized to rid the city of the gang after a particularly violent episode against a Chilean settlement in the city during the summer of 1849. On Monday, July 23, 1849, the vigilantes arrested and made prisoners of 20 of the Hounds, including John Power, who were then arraigned on charges of conspiracy, riot, robbery, and assault with intent to kill; all plead not guilty. While several others were convicted of various charges, Power was found not guilty on all charges.Weekly Alta California, Number 33, 16 August 1849, (Reported for the Alta California.) The Chilenos and other Foreigners in the city of San Francisco attacked by an Armed Party of Americans — Great Excitement — Meeting of the Citizens — Formation of a citizen armed Police — Arrest of the Rioters — Their Trial and Sentence.

Despite being acquitted, Power subsequently left San Francisco for the goldfields. There he was said to have had some success. That August he went to Stockton, the gateway to the Southern Mines, where with $10,000 to $15,000, in a spectacular run of luck, he broke the bank of several large gambling establishments. He acquired a fortune variously said to be $50,000William Redmond Ryan, Personal adventures in Upper and Lower California, in 1848-9; with the author's experience at the mines. Illustrated by twenty-three drawings taken on the spot. W. Shoberl, London, 1850 or $175,000, sufficient to make him a wealthy man. He intended to return by steamboat to San Francisco, then take steamships to New York, where he could take care of his widowed mother, who had remained there when he and his brother had left for California. However, persuaded to attempt to make his fortune larger by gambling, he lost most of it, and never left for New York. Instead he became a noted gambler and horseman in San Francisco and at the resort of Mission Dolores between late 1849 and 1851. By this time he had become known as Jack Power, and was well known to influential people in the city and in state politics.

William Redmond Ryan described meeting Jack Power returning from the Mission Dolores in 1849:

"... Jack Power, one of the sporting characters of the country. Jack had been a volunteer; and, on the disbanding of the regiment, becoming infected with the excitement and adventurous character of the wild life which he had led since his arrival in the country, had devoted himself entirely to gambling and horsemanship, in both of which accomplishments he greatly excelled."

"No matter how low the state of his finances, he was never without a good horse, caparisoned in the true Californian fashion; ... It had, however, this striking peculiarity, that it would never gallop straight forward towards any given point, but would advance in a sort of sidelong canter, very pleasing to behold, but requiring great skill on the part of the rider to maintain his seat. In this eccentric movement of the animal Power took great delight, for it afforded him opportunities of displaying his superior horsemanship."

Ryan went on to say that in addition to his other accomplishments, he was also an excellent performer on the banjo; "and one evening, with three or four others, gave a concert in the dining-saloon of the Parker House, which was suitably arranged for the occasion; and, although the tickets for admission were three dollars each, the attraction of our Nimrod's celebrity ensured a numerous attendance."

Return to Santa Barbara and the Arroyo Burro Affair Power returned to Santa Barbara in 1851. From there he often traveled to San Francisco, Los Angeles and other places to gamble and race horses. During this time he was nearly killed at a ball given by a respected Californio family after insulting the young ladies of the family. He was severely knifed by their young male relatives outside the house. Upon recovering from his wounds he swore to give up his wild life and settle down to a quieter, more industrious life.

In 1852, he established a rancho to raise pigs along the Arroyo Burro on lands formerly belonging to the Mission Santa Barbara that he claimed were public lands he was entitled to settle by the conditions for his service in Stevenson's Regiment. This same land had been leased by Richard S. Den and Daniel A. Hill from the Mission some years earlier. Den also claimed to have an 1846 grant to these lands from the last Mexican governor. Power challenged that claim in the state courts over the next year.

Meanwhile, on June 10, 1851, Jack Power led a 25-man posse against a party of "about 100" armed Native Americans from the San Joaquin Valley that had come to San Buenaventura to trade, some of whom were stealing horses or taking them at gun point. Two men with them were given up to the posse and stolen horses were recovered. These men had murdered a peddler and escaped jail in Santa Barbara, and both also led a gang of horse thieves. They were subsequently tried and hung.Daily Alta California, Volume 3, Number 166, 15 June 1852, p. 5, col. 1 Later From the South. Indian Troubles. In July 1852, Jack was one of a posse that returned two accused murderers, a Californio named Doroteo Zabaleta and a Sonoran named Jesus Rivas, from Santa Barbara to Los Angeles for trial.Los Angeles Star, Number 12, 31 July 1852, p. 2, col. 1-3, Terrible Events. Murder and Its Prompt Punishment

In 1853, a state court case regarding the Arroyo Burro rancho ended with a ruling in Den and Hill's favor. Power refused to leave his rancho after losing his court case in the state district and supreme courts, claiming it was not within the state's jurisdiction to decide the matter but rather the interest of federal courts. Power, with a group of friends, vowed to resist being evicted. Also a member of Stevenson's Regiment, Sheriff W. W. Twist's attempt to evict Power resulted in a bloody clash in the town between some of Power's friends and the sheriff who was organizing a posse of 200 who were about to attempt to eject him from his ranch by force. Twist was badly wounded but managed to kill his assailant, a Californio summoned to serve in the posse. One of Power's friends, John Vidal, a fellow member of Power's company in the Stevenson Regiment, was killed and two others were wounded. Power fled back to his rancho chased by some of the posse.Los Angeles Star, Number 52, 7 May 1853, p. 2, col. 2. Bloody Affray in Santa Barbara — Deplorable State of Affairs. Daily Alta California, Volume 4, Number 126, 7 May 1853, p. 2, col. 1, From San Diego and Los Angeles.Daily Alta California, Volume 4, Number 158, 8 June 1853, p2 col2 The Riot In Santa Barbara Power and his friends including James Lynch, then visiting Santa Barbara, saw them off after they took a few shots at long distance and saw they were well-armed and ready for them.

After a standoff for a period of time, Power was eventually persuaded to leave his ranch after he was granted a lease to harvest his crops and move his stock and possessions off the land.Daily Alta California, Volume 4, Number 143, 24 May 1853, p. 2, col. 3. From San Diego. Following his loss of the rancho, Power continued living in Santa Barbara County, leasing a part of the Rancho Laguna in the Guadalupe Valley, in the north of the county, abandoning pig farming and living by gambling and racing horses as before.

Second conflict with the vigilante movement