The miracles associated with the Rosary over the centuries are so numerous that they could never be numbered. The Rosary has prevented and stopped wars, brought about great conversions, healed marriages, and helped a countless number of souls draw closer to Jesus, his Church, and the Sacraments. Many of these miracles are recorded in the greatest book ever written on the Rosary, The Secret of the Rosary by Saint Louis de Montfort. His book was written in the early 18th century. Since that time, many other miracles have come to light that not even Saint Louis de Montfort was aware of.
For example, in the 17th century, in what is now known as western Texas and New Mexico, a tribe of Jumano Indians bore testimony that they had received numerous visits from a lady dressed in blue who taught them the Catholic faith. This lady also gave them rosaries and taught them how to pray it. Years later, when Catholic missionaries arrived in that area, they were completely baffled when they discovered a tribe of Indians who already knew the Catholic faith and were in possession of rosaries!
At first, when the Indians described their experiences with the lady in blue, the missionaries thought the tribe had been blessed with apparitions of Our Lady. However, upon further investigation, they discovered that the famous Spanish mystic Venerable Mary of Agreda had been bi-locating to the tribe, teaching them the faith, and bringing rosaries with her from her convent in Spain.
Father Donald Calloway, MIC