John Rooney married Ellen Butler in 1865. He is the eldest son of William and Julia Rooney of Chicago. William helped John set-up a diary business on Archer Avenue in the Bridgeport neighborhood during the 1870s. Three of the youngest children were born between the years of 1879 and 1885. The other six siblings were born in Dundee, Illinois. Marie T. Talbot grew up with the Rooney family prior to her marriage to Martin Flanagan in 1922. She was raised by John and Ellen Rooney after her mother Kittie passed away in 1899. Michael M. Byczek is the great-great-nephew of John Rooney, and he has completed the genealogical research associated with members of his family. John had 8 sons and 1 daughter. Four of his sons were involved with politics and law. Thomas was a Chicago alderman from the Bridgeport neighborhood. John was a judge in the Chicago Municipal Court. Edward was deputy clerk of the Municipal Court. Austin was an attorney in the Monadnock Building. The rest of the family were involved with the family business. Ellen Rooney passed away in 1905. John passed away 18 years later in 1923.