You might've chosen a better term to emphasize. History is always valid if it accurately conveys a true story. There are no exceptions, and there cannot be any.
I couldn't of said it better myself. However, every historical account that purports to convey a true story does not always prove to be infallible. If someone came to you and fervently told you that they were abducted by aliens whom of which revealed to them that their alien kin were in fact the source for the creation of humans on this planet long ago, and did it by changing dirt into human beings, would you then consider the whole story to be true even if the abduction part is right? In deciding whether to even believe them at all, you would have to take several things into consideration. First and foremost is their credibility. If it was some base-head off the streets you could most likely dismiss it as delusion. However, if it was a close relative or friend whom you absolutely trust completely, and who has always been level headed with no history of psychosis, you might consider that they actually had the experience. Does it mean what the aliens told them is true? Absolutely not, unless your confidant was there at the beginning of this planet and observed the aliens do this, then you can only entertain the idea inasmuch as your current knowledge allows.
Compare this scenario to the creation story in the bible and two important factors for validity arise. First, in the alien scenario, you have a personal relationship with the person. You have witnessed their behavior and understand to a very good extent their psychology. You know they would not just make something up and believe it whole heartily to be true. Therefore, you have more of a basis for believing them as accurately conveying a true story. However, is all the information in the story infallible? Hardly. This because you know that dirt cannot turn into a human by any natural process. So to even consider the information valid, you would have to entertain the idea that the aliens were somehow magical.
The second factor in considering the validity of historical accuracy, is that your are getting your information from someone who actually had the experience. Your confidant, should you choose to believe them, was actually there on the spaceship, an actual witness to the event. Therefore you are one person removed from the actual historic event.
In contrast, you have no idea what kind of person the author of genesis was. All you have to go on is based on what they wrote, which is hardly an accurate profile to determine their lifestyle or psychological state of mind. They could have used drugs, been two faced liars, or simply delusional; in any event, you would never know. Anyone can write a book and claim it as truth, it is up to the reader to analyze the contents and compare it to what they know to determine if the information is valid. Another factor working against the story of the creation of Adam, is that the storyteller was not there to witness the actual event, nor were they able to interview Adam so that they could convey a firsthand account. Consequently, to decide whether or not the biblical creation story of Adam is true or not, one would have to base their judgment entirely on believing what an ancient author has said he knows about a past event, despite him not witnessing it or interviewing some one who was actually there. If you retreat to the notion that god told him, you will have to explain why god has told different men conflicting things and how you can know if any of them are telling the truth without appealing to personal bias.