He claimed the Heavyweight Championship of America in 1866 by defeating boxer Bill Davis after former champion Joe Coburn retired, and lost the title to Tom Allen in 1873.

[1] McCoole was born on 12 March 1837 in Bally Bulay, County Donegal, Ireland, and came to America at the age of only 13, living first in New York, and then moving West, making a home first around Louisville, Kentucky and Cincinnati, Ohio.

His first recorded bout was in April, 1858 for a purse of $100 against Bill Nary, a well reputed prize fighter, in Louisville, Kentucky, which he won in seventeen minutes and eight rounds.

[1][3][6][5] At the age of 22, McCoole defeated William Blake on Twelve Mile Island in the Ohio off Louisville, Kentucky on 29 June 1859 in thirty-seven minutes, and 29 rounds.

[8] McCoole first fought Joe Coburn for the American heavyweight championship and a purse of $2,000 on 5 May 1863 in Charlestown, Maryland, losing in 67 rounds and in a time of 1:10:00.

The substantial crowd of 2,000 assembled about 30 feet from the shore of the North East River, a remote area, to elude police who may have stopped the fight.

[9][10] McCoole secured the heavyweight championship of America by defeating Bill Davis in 35 rounds and 34 minutes on 19 September 1866 at "Chouteau Island" in Madison County, Illinois.

McCoole's vanquished opponent had fought his last fight, and according to at least one source died several years later, partly from injuries to his lungs caused by his broken ribs in the match.

[1][18][19][20] A large crowd attended the church service as McCoole married a well bred and attractive local Irish girl, Mollie Norton, on August 9, 1868, in St. Louis, though the marriage was brief and troubled.

[23] Nonetheless, the fight took place the following day on 23 September 1873 with a seventh round win by Allen at Chouteau Island in Madison County, Illinois.

McCoole was considered by many historians to be the more awkward boxer, and took the fiercer punishment in the first three rounds, with Allen opening a cut on his right eye, which he continued to pound.

[26] The fight became the greatest loss of McCoole's career as the title, in the view of many current boxing historians, was a world and not merely American heavyweight championship.

McCoole was jailed for a period of time after his arrest, but was later acquitted on 17 February 1875 as the prosecution could not find the principle witnesses to testify.

[30][31] Not long after his arrest, his brush with the law may have caused him to lose his Saloon in St. Louis from lack of patronage, and because he fell out of favor after his loss to Tom Allen.

[26][38][39] He worked aboard the steamer Yazoo off Louisiana as late as 1881, and as a fireman, shoveling fuel to the boiler, on the Earle, a New Orleans harbor boat.

[41][42] McCoole died in financial distress on 17 October 1886, at Charity Hospital in New Orleans, Louisiana, of malaria, and other diseases, and was buried at St. Patrick's Catholic Cemetery, near Canal Street.