Geography
Charleston is located at 39°29′19″N, 88°10′44″W (39.488721, -88.178976)6.
According to the United States Census Bureau, the city has a total area of 8.7 square miles (22.5 km²), of which, 8.0 square miles (20.7 km²) of it is land and 0.7 square miles (1.8 km²) of it (7.84%) is water.
 
Demographics
As of the census7 of 2000, there were 21,039 people, 7,672 households, and 3,329 families residing in the city. The population density was 2,632.2 people per square mile (1,016.7/km²). There were 8,148 housing units at an average density of 1,019.4/sq mi (393.7/km²). The racial makeup of the city was 92.50% White, 4.25% African American, 0.24% Native American, 1.34% Asian, 0.09% Pacific Islander, 0.50% from other races, and 1.08% from two or more races. Hispanic or Latino of any race were 1.76% of the population.
There were 7,672 households out of which 20.2% had children under the age of 18 living with them, 33.9% were married couples living together, 7.3% had a female householder with no husband present, and 56.6% were non-families. 34.6% of all households were made up of individuals and 9.5% had someone living alone who was 65 years of age or older. The average household size was 2.22 and the average family size was 2.88.
In the city the population was spread out with 13.8% under the age of 18, 44.1% from 18 to 24, 18.7% from 25 to 44, 13.7% from 45 to 64, and 9.7% who were 65 years of age or older. The median age was 23 years. For every 100 females there were 86.9 males. For every 100 females age 18 and over, there were 84.5 males.
 The median income for a household in the city was $24,140, and the median ncome for a family was $44,312. Males had a median income of $30,906 versus $21,822 for females. The per capita income for the city was $14,522. About 10.3% of families and 30.1% of the population were below the poverty line, including 8.7% of those under age 18 and 11.8% of those age 65 or over.
 These figures may be somewhat skewed as 10,000 residents of Charleston are students at Eastern Illinois University, many of whom have their primary place of residence in other cities though they spend nine months of the year in Charleston.