One thing that isn't widely known about the Miraculous Medal is that it was originally known as the Medal of the Immaculate Conception. The apparition at Rue de Bac took place 24 years before the solemn proclamation of the dogma. Also, the U.S. bishops declared that Mary under the title of the Immaculate Conception would be the patron of the U.S. in 1846, 8 years before the solemn proclamation.
Great facts for all.