Front and eastern side of the Pulaski County Courthouse, located at 500 Illinois Avenue in Mound City, Illinois, United States. It was built in 1912. – Nyttend, Public domain – Wikimedia Commons Pulaski County is located in Illinois. About 5,193 people live here (as of 2020). Between 2010 and 2020, the population declined from 6,161 to 5,193. The area covers about 527.0 square kilometers. The region is divided into 7 Municipalities. The region was founded in 1843. The name originates from Casimir Pulaski (Polish nobleman) Pulaski County is county in Illinois, United States. More information at www.pulaskicountyil.net.