Career
In 1957 the family moved to Dallas, Texas, where Ferrell found work as a legal secretary. She began collecting materials on the Kennedy assassination immediately after the event. Her assassination database was originally written on over 40,000 cards and included details of over 8,200 people involved in the case.
These data were eventually entered into a computer.
Ferrell also created a four-volume set of chronologies, covering all aspects of the assassination. Ferrell died in Dallas.
The Mary Ferrell Foundation, located in Ipswich, Massachusetts, is a non-profit "devoted to carrying on the legacy of Mary Ferrell, whose integrity and unwavering dedication to truth is an inspiration to many.".