- In Advanced Search, select Content Type: "Primary Sources."
- Bonus: In Advanced Search, select Document Type: "Correspondence" or "Letter" or both. If you want letters from a specific person, topic, or time period, enter a search term, like "Abraham Lincoln." Or just hit "search" to find a variety of letters.
- In NYPL, browse images in Arts and Literature or History and Geography to find manuscripts.
- In Library of VA, search or browse manuscripts relevant to Virginia's history.