From "The Loop" Catholic Vote Weekend edition
According to the Catholic News Agency, the U.S. bishops unanimously named Mary, under her title of the Immaculate Conception, patroness of the nation in 1846, during the Sixth Provincial Council of Baltimore. They declared: “We take this occasion, brethren, to communicate to you the determination, unanimously adopted by us, to place ourselves, and all entrusted to our charge throughout the United States, under the special patronage of the holy Mother of God, whose immaculate conception is venerated by the piety of the faithful throughout the Catholic church.... To her, then, we commend you, in the confidence that ... she will obtain for us grace and salvation.” Blessed Pius IX approved the declaration in 1847.
and From Catholic Answers
https://www.catholic.com/magazine/online-edition/hail-mary-conceived-without-sin
