I went to Wisconsin, so I could visit the Shrine of Our Lady of Good Help, located in an unincorporated town called Champion. It's about fifteen minutes northeast of Green Bay. The shrine is built where the Virgin Mary appeared three times to a Belgian woman named Adele Brise. Adele later became Sister Adele and dedicated her life to teaching children, as the Blessed Mother requested.
This happened in 1859. At that time, they only had one priest to cover a large area in Wisconsin. There was no way that he could take care of everything by himself. As a result, a lot of the Catholics ended up doing non-Catholic things, like supporting slavery or worshipping saints, simply because they weren't educated in true church teachings. Therefore, Sister Adele's mission was both noble and necessary.
The problem of people not knowing church teachings happens a lot today, too, even though we have the Internet, and people can easily get information. For example, you'll sometimes hear Catholics complain that they don't know what the word "consubstantial" means; the odd part is that they rarely go through the trouble of looking up the definition.
Even though the apparitions took place in 1859, the local Bishop did not give official approval to it until 2010. You can't blame the Bishop for taking a long time with the process. There have been at least three Marian apparitions in the United States which were proven to be hoaxes upon official investigation. Here is what the Bishop said in his offical document: "I declare with moral certainty and in accord with the norms of the Church that the events, apparitions and locutions given to Adele Brise in October of 1859 do exhibit the substance of supernatural character, and I do hereby approve these apparitions as worthy of belief (although not obligatory) by the Christian faithful."