Post a flyer in the history and english depts. of your local university. Offer to pay by the article, maybe $5 - $10 (after verification of unique work, which you have to do anyway). You will have more than you can use.
I paid per article as I needed five articles on specific topics. I don't know if we're allowed to list actual prices. But, it was pretty darn reasonable, especially considering that the topic the articles were on were highly technical and probably required more research than the average article (thus why I didn't want to do them myself LOL).