> Yes, we use written records and they help greatly in our
> understanding of what we are looking at, but written documents generally fail
> to record many important facets of life - how people lived, what they ate,
> who they interacted with in a community and why, what material culture
> changes took place over time in a particular locality,  what the particular
> ethnic make-up of a particular site or  community may have been, how a
> commercial establishment fit into a community's social structure, how a
> milling process was carried out at an industrial site, and a thousand other
> questions.  Also, though the written record may touch on some subjects, it is
> almost always incomplete, leaving out critical details which help us in a
> better understanding of a site, a people or an industrial process.
> One other critically important reason for historic archaeology, and one that
> able to compare the historic record and the archaeological record and find
> out just how close (or more often how far off) we are in our analysis of
> sites.  Such comparisons allow us to refine our future assessments of data
> and, hopefully, get a little more accurate in our conclusions.
 
Also, let's remember that it was the people in power or that took power
that wrote down what happened.  The subjugated peoples probably did not
get their version down on paper.