I live in the Diocese of Green Bay, and we are fortunate to have in our community the National Shrine of Our Lady of Champion. This is the only church approved Marian apparition site in the United States. It's located in the small town of Champion, WI, and is therefore often called simply the "Champion Shrine".
On April 20, 2023, Bishop David Ricken issued a decree officially changing the name from "National Shrine of Our Lady of Good Help" to the "National Shrine of Our Lady of Champion".
These are some links to help you get familiar with the Shrine, its history, and the miracles that have happened there.