If you've never read David Macaulay's wonderful book Motel of the Mysteries you owe it to yourself to find a copy and read it! It is a fable about how attempts to interpret traces of the past can go spectacularly wrong and it should be required reading for all archaeologists.
Joking aside, however, you shouldn't think that all claims about the past are equally likely to be wrong. I may not be able to interview people from Ohio's ancient past, but I can interrogate the physical evidence they left behind and gain real insight from it. For example, 19th century claims that Fort Ancient served as an actual fortification have been disproven by the lack of the predicted evidence for warfare at the site (no profusion of spear points or human remains with battle wounds) as well as clear evidence of the unsuitability of the site for defense (it's too big with too many gateways and the "moats" are on the inside of the walls instead of on the outside where you would expect them to be if they were built as defensive structures).
Here's the link for Number 8: