From Aleteia:
When 250 Catholic bishops gather in Orlando, Florida, on June 11, they will be in the presence not only of the Shroud of Turin exhibit but also of the relics of St. Margaret Mary Alacoque. Consecrating the nation to the Sacred Heart on the occasion of its 250th anniversary, the bishops will have the blessing of venerating relics of the French sister to whom the Sacred Heart was first revealed.
St. Margaret Mary was a religious living in the Monastery of the Visitation in Parais-le-Monial in 1673 when she began having visions of Jesus. He showed her his Sacred Heart, on fire with love for humanity. She shared her visions with her confessor, the Jesuit St. Claude de la Colombiere, who, along with his Jesuit brothers, encouraged the spread of devotion to the Sacred Heart.