Sterling is a city in Whiteside County, Illinois, United States. The population was 14,782 at the 2020 census, down from 15,370 in 2010. Formerly nicknamed "Hardware Capital of the World", the city has long been associated with manufacturing and the steel industry. Geography Sterling lies along the north bank of the Rock River, opposite its twin city, Rock Falls. The terrain is mostly flat. The land immediately outside of town is almost entirely farmland. The prairie soil is part of one of the world's most fertile growing areas. According to the 2010 census, Sterling has a total area of , of which (or 96.08%) is land and (or 3.92%) is water. Demographics As of the census of 2000, there were 15,596 people, 6,234 households, and 3,946 families residing in the city. The population density was . There were 6,596 housing units at an average density of . The racial makeup of the city was 84.36% White, 2.25% African American, 0.41% Native American, 0.81% Asian, 0.01% Pacific Islander, 9.82% from other races, and 2.35% from two or more races. Hispanic or Latino of any race were 19.24% of the population. There were 6,234 households, out of which 30.3% had children under the age of 18 living with them, 47.2% were married couples living together, 12.2% had a female householder with no husband present, and 36.7% were non-families. 31.4% of all households were made up of individuals, and 14.0% had someone living alone who was 65 years of age or older. The average household size was 2.41 and the average family size was 3.04. In the city, the population was spread out, with 25.1% under the age of 18, 9.5% from 18 to 24, 28.7% from 25 to 44, 19.8% from 45 to 64, and 16.9% who were 65 years of age or older. The median age was 36 years. For every 100 females, there were 90.9 males. For every 100 females age 18 and over, there were 86.9 males. The median income for a household in the city was $37,664, and the median income for a family was $45,531. Males had a median income of $33,047 versus $21,944 for females. The per capita income for the city was $19,432. About 7.6% of families and 10.8% of the population were below the poverty line, including 17.0% of those under age 18 and 5.4% of those age 65 or over. History In 1834,