From the very beginning, and before time began, the eternal Father chose and prepared for his only-begotten Son a Mother in whom the Son of God would become incarnate and from whom, in the blessed fullness of time, he would be born into this world. Above all creatures did God so love her that truly in her was the Father well pleased with singular delight. Therefore, far above all the angels and all the saints so wondrously did God endow her with the abundance of all heavenly gifts poured from the treasury of his divinity that this Mother, ever absolutely free of all stain of sin, all fair and perfect, would possess that fullness of holy innocence and sanctity than which, under God, one cannot even imagine anything greater, and which, outside of God, no mind can succeed in comprehending fully.
Saturday, December 8, is the Solemnity of The Immaculate Conception of the Blessed Virgin Mary; Patronal Feastday of the United States. Even though this Feastday falls on a Saturday it is still consider a Holy Day of Obligation. Mass times are 7:00 a.m., 9:00 a.m. and 11:40 a.m. The regular weekend Mass will be celebrated at 5:30 p.m.
Excerpts: Apostolic Constitution of Pope Blessed Pius IX solemnly defining the dogma of the Immaculate Conception, December 8, 1854.