James Haggerty was born in Philadelphia, Pennsylvania to a large working-class family near the banks of the Schuylkill River; his boyhood home was located on Arch Street in the area between Eighteenth and Nineteenth Street known as "McAran's Garden". His father, John Haggerty, was a "boss" drayman widely respected by the local business community "as an honest, upright and faithful servant". Haggerty remained free of criminal activity during his childhood, however he did not attend school and received little education.

Jimmy Haggerty age 21 became employed a mule driver for the Reading Railroad. He continued in this profession, as well as ran a local saloon, until the start of the American Civil War in which he voluntarily enlisted in the Union Army.^[7]

Although it is unknown under the exact circumstances he left the service, whether he received an honorable discharge or took "French leave", he soon became a "bounty jumper". He became acquainted with a number of known criminals during this time and, returning to Philadelphia following the war, became involved in illegal bare-knuckle boxing and eventually petty theft, armed robbery and burglary. Although he was considered extremely violent when drunk, police officers testified to his reluctance to murder a victim in cold blood and described the frequent use of his pistol as a blackjack in confrontations, he was connected to a number of major robberies during his career. Among them were the robberies of the Eleventh Street and Chestnut Street Banks, the Philadelphia Savings Bank and the safe burglary of the Dancannon Iron Works. He was also involved in the robbery of White's Dental Depot where an African-American watchman was murdered.^[7]

After numerous arrests for theft and similar offenses, he and Hugh Murphy were convicted of the robbery of a Ninth Street store and sentenced to ten years imprisonment on December 12, 1865. He was pardoned by Governor Andrew G. Curtin eight months later, in part to Haggerty's political connections and his promise to leave the country upon his release, and lived in Canada for a brief time before returning to the city to resume his criminal career. Haggerty remained a major underworld figure in Philadelphia until January 1869 when he was arrested on several counts of assault with intent to kill; during his arrest, he shot the arresting police officer.^[7]

He was caught trying to escape from prison but was later released on bail and fled the city. Staying in New York for a brief time, he returned to Philadelphia in April to surrender himself to authorities after the wounded police officer had received "hush money". He won both court cases against him, but was ordered at the second trial to return to the Eastern State Penitentiary by the District Attorney for violating the terms of his release. While his lawyers argued the ruling, Haggerty escaped from the courthouse during a recess in what was suspected to have been planned.^[7]

He eventually returned to New York where he resided during the last two years of his life. He was involved in disputes with a number of criminal figures, for example, when he and Billy Tracy were thrown out of a Bowery gambling resort by its owner Harry Hill and British lightweight boxer Billy Edwards in November 1870.^[8] On the afternoon of January 24, 1871, Haggerty and three others arrived at Jem Mace's Capitol Saloon on Twenty-Third Street. They had become intoxicated while traveling by sleigh along Harlem Lane and, shortly after their arrival, they became involved in a violent altercation with another group of patrons. It was thought that Haggerty and his party were about to use their pistols when a local patrolman and a City Hall officer arrived from nearby Booth's Theater. At the appearance of the patrolman walking through the saloon door, Haggerty drew his revolver and pistol whipped him sending the officer outside. As the two officers went to get reinforcements, Haggerty and his men made their escape on the sleigh. His whereabouts remained unknown until early the next morning when he entered Patrick Egan's saloon. While there, his friend Billy Tracy became involved in a dispute with Shang Draper stemming from the earlier dispute at Jem Mace's saloon. Reddy the Blacksmith, a longtime member of the Bowery Boys, attempted to separate the two but Haggerty confronted Reddy and demanded that he stay out of it. As the two argued, Haggerty reportedly attempted to grab a decanter from the bar to strike the Bowery Boy with causing Reddy to draw his pistol and shot Haggerty in the abdomen. Haggerty was taken to a room in West Houston Street where claimed he did not know either Tracy or Draper and that he was so intoxicated that he was unable to recognize who fired the shot. Although mortally wounded, an examination finding the bullet had penetrated his intestines, Haggerty refused to name his attacker and died from his wounds later that evening.^[9]

His funeral was perhaps one of the biggest held in Philadelphia's history and took place at his mother's residence at the northeast corner of Twenty-Third and Filbert Streets, the longtime headquarters of Schuylkill Rangers, and was attended by what was thought to be one of the largest criminal gatherings of the era. Among the hundred or so mourners included Squire McMullin, John Ahern and Robert Lister Smith.^[10]

An official inquest was held in the days following his death, attracting a number of prominent criminals such as Dan Noble, Joe King, Johnny Moore, Richard Barron and Broker Dick among others,^[11] before it was finally concluded on February 1 with Reddy being released on a $10,000 bail.^[12]