Our Lady of the Immaculate Conception is a title given to the Virgin Mary, recognized in the Catholic Church as being conceived without original sin. This belief emphasizes her purity and special role in salvation history. The feast day is celebrated on December 8, and it is a significant event in the Catholic liturgical calendar. The doctrine of the Immaculate Conception was formally defined by Pope Pius IX in 1854. This title is often associated with the United States, where she is the patroness, and many churches and institutions are dedicated to her. The image of Our Lady of the Immaculate Conception is commonly depicted with symbols of purity, such as flowers and a crescent moon.