We honor the historical record, but understand that its interpretation constantly evolves as historians analyze primary documents in light of the ever-expanding body of secondary literature that places those documents in a larger context. By "documents," historians typically mean all forms of evidence-not just written texts, but artifacts, images, statistics, oral recollections, the built and natural environment, and many other things-that have survived as records of former times. By "secondary literature," we typically mean all subsequent interpretations of those former times based on the evidence contained in primary documents. This distinction between primary and secondary sources is among the most fundamental that historians make. Drawing the boundary between them is a good deal more complicated than it might seem, since determining whether a document is primary or secondary largely depends on the questions one asks of it. At the most basic level, though, the professional practice of history means respecting the integrity of primary and secondary sources while subjecting them to critical scrutiny and contributing in a fair-minded way to ongoing scholarly and public debates over what those sources tell us about the past. [from the AHA's Statement of Standards]
A page created by the Library of Congress for teachers on how to use primary sources.
There are a variety of methods for locating primary sources. One of the best is to pay attention to the sources that scholars have used in their research. If your secondary sources cite accurately and fully, they will lead you to the primary sources. You can also identify dissertations on your topic. A dissertation often includes more sources than otherwise might be included because the student is trying to convince his or her committee that he/she knows the parameters of the research in the field. You can also search the WWW, using various keywords or ask your professor or a librarian who might have knowledge of specific sources. I have not attempted to list any here because the research assignment is very broad, covering 500 years of history and many possible cities.
