Yes, you are right. Technically the U.S. was still an English colony. This isn't about stories in France or anywhere else. It was about something happening on the North American main land.
The keyword here is "documented". Something that was looked at, written down and investigated by science of the times. Several hundred years form now today's science and medicine with seem stone age. So don't judge their science.
Just like the Roff possession. Mary Roff was the first "documented" case of possession in Illinois. Written, recorded and investigated by science of the time.
There is an old house in Eldred Illinois that sometimes has stone appear in mid air and fall to the ground. I have never seen this happen myself but, I've investigated the house only once. My experience was the the room was empty and I along with 2 other investigators were in another room. We heard some noise as if something was dropped. When we went into the room to investigate, there were some stones on the floor where none was before. Unfortunately we didn't have any cameras set up at the time.