The best way to find historical societies is to use an Internet search engine. Enter the name of the county and state along with "historical society" or "history center" in the search line. Your next step is to find out what is in the collection at that center.
If you are not sure what type of queries to use with a seach engine, the online advice feature of this site will set up the proper search engine queries for you. Click here to go to online advice.
If you are not sure that an historical society is the next best option for your research, consider using the advice feature of this site. This will help you pick your next best steps in your research. Go to Genealogy Search Advice.