The Ancient Egyptians Visited the Grand Canyon
A newspaper article from the early 1900s claimed that a group of Smithsonian-funded archeologists had been exploring caves in the Grand Canyon—places where almost anyone had ever looked—and had made an amazing discovery. The discovery of ancient Egyptian remains in the cave suggests that the Egyptians were able to use a form of sea transit that was sufficiently developed to reach such a remote continent, even though a little cave would only suggest a scouting mission. Due to the recent popularity of hypotheses about ancient aliens, which invariably prominently involve the ancient Egyptians, these assertions have recently come back into the public consciousness.
Although it would be fantastic to assume that the Egyptians actually accomplished such a feat—the historical ramifications would be incredible—there is actually no proof that such an expedition took place. The Smithsonian has consistently disputed that the two "archeologists" in the news report ever worked for them or took such a trip, and they have made it clear that they don't think there has ever been any activity related to the ancient Egyptians in the Americas.
The Smithsonian, according to some who want to believe it, has allegedly concealed numerous pieces of evidence over the years in order to support the thesis that the Egyptians never lived in this area. This would be absurd, of course, as we would very certainly have more concrete proof of their presence by this point, even if there had been some clumsy attempt at a cover-up. Additionally, if this incredible cave of artifacts were true, it seems plausible that someone would have disseminated information on where to discover it.