Our Lady of Ransom is connected to the Order of Mercedarians, who sought to free Christian captives.
September 24 is a special feast day celebrated in many Spanish- and French-speaking countries that honors Our Lady of Ransom.
In Spanish the feast is titled Virgin de la Merced. Merced means grace, benefit, mercy, and the Order of Mercedarians promoted devotion to Our Lady under this title.
According to the University of Dayton, “Our Lady of Ransom is a Marian title commemorating the foundation of the Mercedarian religious order by St. Peter Nolasco in 1218 … St. Peter Nolasco founded the order in response to a request made by the Blessed Virgin during an apparition on August 1, 1218. Members of this order took a special vow to act as hostages, if necessary, to free Christian captives whose faith was in danger from the Moors.“
As a result, September 24 became a day historically associated with praying for prisoners, as well as for releasing captives.
Devotion to Virgin de la Merced is now more focused on our spiritual chains and breaking free from slavery to sin.