Putnam County
Also known as Putnam County, Illinois, Putnam County, IL
county in Illinois, United States
Key facts
- Country
- United States
- State
- Illinois
- Named after
- Israel Putnam
- Seat
- Hennepin
- Largest village
- Granville
- Total
- 172 sq mi (450 km )
- Land
- 160 sq mi (410 km )
- Water
- 12 sq mi (31 km ) 7.0%
- Estimate 2025
- 5,619
- Density
- 35/sq mi (14/km )
- Time zone
- UTC−6 ( Central )
- Summer dst
- UTC−5 ( CDT )
- Congressional districts
- 14th , 16th
Article
Putnam County is the least extensive county in the U.S. state of Illinois. According to the 2020 United States census, it had a population of 5,637. The county seat is Hennepin. The county was formed in 1825 out of Fulton County and named after Israel Putnam, who was a general in the American Revolution. Putnam County is part of the Ottawa, IL Micropolitan Statistical Area.
Geography