According to the dogma of the Immaculate Conception, Mary, the Mother of God, was free from the instant of her conception from the taint of original sin on account of the merits of Jesus Christ, Who was to suffer and die on the cross. Bl. Pius IX defined this dogma in 1854, citing Scripture and Tradition. Four years later, the Blessed Virgin appeared to St. Bernadette Soubirous at Lourdes and identified herself as the Immaculate Conception -- a term the uneducated country girl did not understand. The Mother of God had never before so identified herself: Queen of Heaven though she is, she waited until her Son's Vicar on earth stamped that title with his authority.
I look back on the blog and find a fair number of posts about the Immaculate Conception. Here are the choicest:
Excerpts from Ineffabilis Deus, in which Bl. Pius IX defines the dogma of the Immaculate Conception.
Mary's assigned role in the work of our redemption required the unparalleled grace of the Immaculate Conception.
The popular song "Mary, Did You Know" should be rejected by Catholics as a flat denial of the dogma of the Immaculate Conception.
Potuit, decuit, ergo fecit: those who reject the Immaculate Conception are hopelessly mistaken about God Himself.
Queen conceived without original sin, pray for us who have recourse to thee.