The bulk of his collection is comprised of notes by Fiske on Greek Language and Literature, Mental and moral philosophy and American History, in which he apparently had an interest.

This collection is organized into five series:

• 1. Correspondence
• 2. Notes for Lectures on Greek Literature & Philosophy, Mental Philosophy, Sacred History, Ancient Geography, American History
• 3. Published Works
• 4. Works about Fiske
• 5. Miscellaneous