I just located my great-grandfather's Naturalization card (I think). How do I get the paper work & information he must have filed to receive his card? It's dated Oct 16, 1860 in Morrison, IL. His name was Francis Frank.
I assume that this is the index record that you found:
He was naturalized at the Circuit Court in Whiteside Co, IL. It looks like these naturalization records are at he Northern Illinois University branch of the Illinois State Archives https://www.ilsos.gov/isa/localGovRecordsSearch.do (enter Whiteside and naturalization in the county & title search boxes).