According to extra-biblical tradition, the birth of Mary was preceded by the prayerful lives of Saints Anne and Joachim. Childless, hopeless like Abraham and Sarah, they prayed to God for a child. An angel appeared to St. Anne and told her that their prayers would be answered and that she would bear a child. During the pregnancy, the angel continued to instruct them about the graced nature of their child.
The Holy Spirit had worked through the family of the House of David to select two holy people to cooperate with God's plan for salvation. Such holiness did not go unrewarded, since the Church from earliest times has proclaimed that Mary was immaculately conceived, without the sin of our human race, from the first moments of her existence. In 1854, the Church confirmed this belief by declaring Mary's Immaculate Conception a dogma of the Church. By an anticipation of the touch of the Incarnation and the Virgin Birth that would mark her life as a young woman, God claimed Mary for his own from her conception.
From the earliest centuries, the Church in the East and West has celebrated the birth of Mary, the Mother of God. In the Roman Missal, the feast is proclaimed on September 8. Since the nineteenth century, the Feast of the Immaculate Conception of Mary has been celebrated on December 8. Under that title, Mary has been proclaimed the holy patron of the United States of America.