Since Maryland was established as a Catholic haven in 1629, I’m pretty sure it’s well known there were Catholics in America well before the 1800s.
In the article, they talk about Maryland.
Here is something that I was thinking. I read the entire piece to see if one of the researchers presented this possibility. Is it possible that he had no idea that this item would be buried with him? Was there someone close to him who chose to bury it with him even though he was an Anglican? Or could it be that it was not actually buried with him but just hidden in the soil of his freshly-filled grave by someone intending to retrieve it at a later date?