Pulaski County is a county in the U.S. state of Arkansas with a population of 391,284, making it the most populous county in Arkansas. Its county seat is Little Rock, which is also Arkansas's capital and largest city. Pulaski County is Arkansas's fifth county, formed on December 15, 1818, alongside Clark and Hempstead counties. The county is named for Count Casimir Pulaski, a Polish volunteer who saved George Washington's life during the American Revolutionary War.