Wayne County, Tennessee  Wayne County is a county located in Tennessee. As of the 2010 census, the population was 17,021. Its county seat is Waynesboro. The county is named after General "Mad Anthony" Wayne. Wayne County was created in 1817 from parts of Hickman and Humphreys counties. Waynesboro, its county seat, was established in 1821. The city of Clifton emerged as a key river port in the mid-19th century. According to the U.S. Census Bureau, the county has a total area of , of which is land and (0.2%) is water. It is the second-largest county in Tennessee by area. The county lies primarily along the southwestern Highland Rim. The Tennessee River flows along Wayne County's northwestern border with Decatur County. The Buffalo River, a tributary of the Duck River, flows through the northern part of Wayne County. The Green River, a tributary of the Buffalo, flows through Waynesboro. As of the census of 2010, there were 17,021 people, 5,822 households, and 4,321 families residing in the county. The population density was 23 people per square mile (9/km²). There were 6,701 housing units at an average density of 9 per square mile (4/km²). The racial makeup of the county was 92.3% White, 5.7% Black or African American, 0.3% Native American, 0.2% Asian, 0.01% Pacific Islander, 0.19% from other races, and 1.0% from two or more races. 1.6% of the population were Hispanic or Latino of any race. There were 5,936 households out of which 31.00% had children under the age of 18 living with them, 59.10% were married couples living together, 10.10% had a female householder with no husband present, and 27.20% were non-families. 24.40% of all households were made up of individuals and 10.90% had someone living alone who was 65 years of age or older. The average household size was 2.47 and the average family size was 2.93. In the county, the population was spread out with 21.40% under the age of 18, 9.10% from 18 to 24, 31.70% from 25 to 44, 24.20% from 45 to 64, and 13.60% who were 65 years of age or older.