Some years after the first Catholic missionaries began working in North America, a pair of Indians from a western tribe (I believe it was the Nez Perce) showed up in St. Louis looking for some men they called the "Black Robes." This was the second pair of Indians that had been dispatched in search of these missionaries -- the first pair had been sent out a couple of years earlier but had never been heard from again.
When asked why they were looking for these "Black Robes," the Indians said that they were sent to find them because "we heard they have good medicine." ("medicine," it should be pointed out, was their word for "wisdom"). It turns out that some of the missionaries' teachings had made their way westward over time as the region was slowly settled, and a few of the tribes living out there were very quick to pick up on them. In fact, they knew right away that what the "Black Robes" were saying made far more sense than the earth-worship nonsense that most native tribes accepted as the truth up to that point.