Question: When did the first apparition of the Blessed Virgin take place? (R.D., Illinois)
Answer: Mary first appeared in Nazareth around 20 B.C. But the questioner is obviously asking about a mystical phenomenon. A possible candidate for the first Marian apparition is the vision of Saint John in Apocalypse xii: 1, "a woman clothed with the sun, and the moon was under her feet, and upon her head a crown of twelve stars." Some conjecture that the woman was the Blessed Virgin -- and such a moon and stars appear on the Miraculous Medal of our Lady. Yet, Saint John continues, "And being with child she cried out in her travail and was in the anguish of delivery." It is generally agreed that the Blessed Virgin, never being subject to original sin, would not have been subject to the pains of childbirth, so she is likely not to be the woman in "travail" and "anguish." Some interpreters hold that the Woman is a figure of the Church, which certainly does undergo pains and difficulties.
Probably, the first recorded Marian apparition was to Saint Gregory the Wonder-Worker, Bishop of Neo Caeserea, who died in 270 A.D. The account of his vision is preserved by St. Gregory of Nyssa in his life of the Wonder-Worker:
The first apparition of Our Lady that was investigated by the Church in order to allow public veneration in modern times seems to be that of Our Lady of Guadalupe:
In Mexico, in the year of our Lord 1531, according to holy tradition, Mary, the Virgin Mother of God, appeared on Mount Tepeyac to a recently baptized Christian, Juan Diego, and gave him a message for Bishop Juan de Zum rraga -- a commission which she urgently repeated -- that a church was to be built there in her honor. The bishop, however, asked for a sign. Two days later the neophyte set out to get a priest to administer the Last Sacraments to his uncle, and he took a route that would not bring him too near the place of the apparitions. But his loving Mother favored him with a third visit, assured him of his uncle's good health, and had him gather some roses that had sprung up out of season. These she arranged in his tilma or cloak, and she told him to take them to the bishop. As the roses cascaded to the floor of the bishop's audience chamber, a picture of Mary, miraculously imprinted on the tilma, was visible by all present. The image was at first kept in the bishop's oratory, and then moved to the hermitage that had been built on Mount Tepeyac, and then finally placed in the great basilica which became the goal of crowds of Mexican pilgrims, drawn there by their devotion to Mary and by the reports of frequent miracles. Having the Blessed Virgin Mary of Guadalupe as an ever present protectress, the Mexican bishops with the approval of all their people, chose her as the primary patron of the Mexican nation. This choice was duly approved by the apostolic authority of Pope Benedict XIV. On Columbus day, October 12, 1895, Pope Leo XIII, acting through the Archbishop of Mexico, adorned the holy image with a golden crown. Saint Pius X declared Our Lady of Guadalupe Patroness of all of Latin America.
--- Roman Breviary, December 12
In recent times, the October 12th feast has spread to honor our Lady as "Patroness of the Americas," both North and South.