Rigney was born in Chicago to John Louis Comiskey (1885–1939) and Grace Elizabeth Reidy (1894–1956).
[1] She was the eldest grandchild of Charles Comiskey, and inherited control of the White Sox upon the death of her mother.
When Dorothy put the team on the market after the 1958 season, she initially wanted to sell her 54% stake to her brother.
[3] However, Chuck made such a lowball offer that Dorothy instead sold the White Sox to Bill Veeck, ending the Comiskey family's 58-year control of the franchise.
One of her most successful runners was multiple stakes race winner, Fast Hilarious, whose wins included the 1969 American Derby and the 1971 Gulfstream Park Handicap.