Geoghegan claimed the Lightweight Championship of America in 1861, and held it until his retirement in 1863. He stood 5’ 6”, and weighed between 130 and 140 pounds.
Patrick “Scotty” Brannagan retired as Lightweight Champion of America in 1861, and a contest was held between Geoghegan and Eddie Touhey to fill the vacant title. The two men met on April 18, 1861 in New York. Although Toughey was a better boxer, Geoghegan wore his opponent down with his incredible strength. After 45 rounds, and 61 minutes, Geoghegan was declared the new champion.
Between 1861 and 1863 he defended his title against Bob Slaon, Chick Sullivan, Banty Edwards, and Pat Devlin before being challenged by the 144-pound Con Orem.
The bout between Geoghegan and Orem took place near South Amboy, New Jersey on May 15, 1863. After 19 rounds and 23 minutes, Geoghegan was declared the winner, when his opponent committed an illegal foul. After this contest, Geoghegan relinquished his title and retired from the ring.