Working with archival materials is a key component to historical research. Identifying which archival materials to consult can be a challenge. I encourage you to:
Read widely in reference and secondary sources on your topic and the time period you are studying to inform your archival research.
Look closely at the websites of archival repositories to learn about their collections, finding aids, and procedures.
Keep a running list of the relevant people, organizations, events, places, dates, and themes you discover in your reading and use that information to guide your search. Use that list to inform keywords and phrases to use in your searching.
You are always welcome to reach out to me for more assistance.
Find the locations of physical archives around the state, around the country, and around the world.