Putnam County is the least extensive county in the U.S. state of Illinois. According to the 2020 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,... Wikipedia
Population: 5,572 (2022)
County seat: Hennepin
Area: 172 mi²
Founded: 1825
Largest village: Granville
Named for: Israel Putnam