God, choosing Mary centuries ago as the Mother of His Son, preserved her from every stain of sin and gave her fullness of grace. For this reason, Mary became the worthy home of the Incarnate Word. By thanking God for the unique privilege granted to Mary, we ask for the grace to overcome sin. The Feast of the Immaculate Conception was celebrated in the East as early as the 8th century.

The truth about the Immaculate Conception of Mary is a dogma of faith. It was solemnly announced on December 8, 1854, by Pope Pius IX in the Basilica of St. Peter in Rome in the presence of 54 cardinals and 140 archbishops and bishops. The Pope wrote: We declare, decree, and define that the doctrine which holds that the Blessed Virgin Mary from the first moment of her conception - by a special grace and privilege of Almighty God, by the merits of Jesus Christ, Savior of the human race - was preserved immune from all stain of original sin, is truth revealed by God and therefore all believers should believe in it persistently and without hesitation.

The Immaculate Conception of the Blessed Virgin Mary is celebrated as the patronal feast day of the United States of America and is a Holy Day of Obligation.