This may be more an /his/ topic but theories and possible cover ups about people from Asia, Europe, and other places visiting and maybe attempting to settle in the New World seems like a good topic for /x/.
So what some of your favorite theories and out of place artifacts /x/?
I have a story from my local area that happened in the 1800s yet got me thinking about the possibility of China or Japan reaching North America earlier
>The first Japanese known to have visited what is now Washington arrived in a dismasted, rudderless ship that ran aground on the northernmost tip of the Olympic Peninsula sometime in January 1834. The ship had left its home port on the southeast coast of Japan in October 1832, with a crew of 14 and a cargo of rice and porcelain, on what was supposed to be a routine journey of a few hundred miles to Edo (Tokyo). Instead, it was hit by a typhoon and swept out to sea. It drifted across some 5,000 miles of ocean before finally reaching the Northwest coast with three survivors. Their names were Iwakichi, Kyukichi, and Otokichi. Found and briefly imprisoned by Makah Indians, the "three kichis" spent several months at Fort Vancouver before being sent on to London and eventually to China. They became pawns in the diplomatic chess game that governed Japan’s relations with the outside world in the mid-nineteenth century, and were never able to return to their homeland.
Now this story made think, if by chance some sailors in a damaged ship that likely wasn't prepared or even built for the open ocean managed to drift all the way to west coast why couldn't a well stocked expedition of ships manage the journey as well?
There's all sorts of interesting stuff in NA. nordic rune stones farther south than the vikings where ever known to go and conspiracy theories that the Smithsonian would intentionally misplace and lose artifacts that didn't fit with the established historical narrative.