Scanning through old newspapers can be a great source of local AC history. I found these local dealership ads in our area newspapers. Check your local library for newspaper microfilms. You can also access some newspapers on Google Newspaper Archive or Newspaper Archive. Addition sources may be available through local historical societies, universities, and libraries.
Austin M. Frederick 
Can I access old Markesan Herald papers online?
No, unfortunately they are only available in microfilm at the Markesan Public Library, or in bound copies at the Markesan Historical Society.