I think you are confusing history with archeology. They are obviously related, but they are not the same thing. Preserving history requires keeping it alive. Those books you speak about were endlessly copied and read. I am willing to bet that most of you know about history you have learned from articles or books of people who read other books, and so on. Archeology steps in when history ends up as a CD-in-a-box or tablet-in-a-tomb. And even then we often loose context and meaning.