Please note that a number of these resources contain both primary and secondary sources. For example, some include an image or text, then information added by modern authors to add information relevant to the source. The image/text would be a primary source, while the author's information would be a secondary source. If in doubt, review "What is a Primary Source?" on the main Primary Sources page, ask me, or ask Dr. Vail.
Sources are generally included in only one category, so make sure to skim all categories if you're not finding something.