Jack O'Brien's lastname was Hagan. His parents came to Philadelphia from the Draperstown area of County Derry. He is supposed to be related to my Hagan's. Kathy May 26, 2010 01:54:45 PM, paphilad@rootsweb.com wrote: Has anyone ever heard of a boxer who went by the name of Philadelphia Jack O'Brien? It was not his real name just the name he boxed under. It is said he boxed in the lightweight division and later had gym in downtown Philadelphia. I don't know the timeframe---but I know it was before the 1920's--maybe 1870-1900? Thank you. Elaine *********e