Mary appeared to Saint Catherine Laboure and told her "My child I am going to give you a mission."
The Meaning of the front side of the Medal
Mary gave Saint Catherine a globe that had the word “France,” and our Lady explained that the globe represented the whole world, but especially France
The Meaning of the back side of the Medal
The vision changed to show our Lady standing on a globe with her arms now outstretched and with the dazzling rays of light still streaming from her fingers. Framing the figure was an inscription:O Mary conceived without sin, pray for us who have recourse to thee.
Mary is standing upon a globe, crushing the head of a serpent beneath her foot. She stands on the globe, as the Queen of Heaven and Earth.
The twelve stars refer the Apostles. The cross can symbolize Christ and our redemption, with the bar under the cross a sign of the earth. The “M” stands for Mary,
Then Mary spoke to Catherine: “Have a medal struck upon this model. Those who wear it will receive great graces, especially if they wear it around the neck.” She did not reveal that she received the Medal until soon before her death 46 years later. The first Medals were made in 1832 and were distributed in Paris