Online Databases:
- Switzerland County Naturalizations 1814-1872
- Switzerland County Naturalizations 1858-1860
- Switzerland County Naturalizations 1862-1918
- Naturalization papers can be found in the court and probate packets
- Switzerland County Naturalizations Index – Indiana State Digital Archives (free)
Family History Library Microfilm:
- Naturalization Records (1858-1860) – FHL 1310470
Books:
- An Index to Naturalization Records in Pre-1907 Indiana County Courts. Indiana Historical Society : Indianapolis, 2001.