1854 : The Dogma of the Immaculate Conception (Catholic Church)

The Apostolic Constitution of Pope Pius IX on the Immaculate Conception of December 8, 1854, proclaimed the Dogma of the Immaculate Conception:

We declare, pronounce, and define that the doctrine which holds that the most Blessed Virgin Mary, in the first instance of her conception, by a singular grace and privilege granted by Almighty God, in view of the merits of Jesus Christ, the Savior of the human race, was preserved free from all stain of original sin, is a doctrine revealed by God and therefore to be believed firmly and constantly by all the faithful.