|Name origin: Friedrich Franz Karl Hecker, German revolutionary, orator, and American Civil War Colonel|
|Area||0.24 sq mi (1 km2)|
|- land||0.24 sq mi (1 km2)|
|- water||0.00 sq mi (0 km2)|
|Density||1,993.8 / sq mi (770 / km2)|
|- summer (DST)||CDT (UTC-5)|
|Wikimedia Commons: Hecker, Illinois|
Hecker was originally named Freedom. The town was laid out on land of Theodore Hilgard. It was platted and surveyed by Thomas Singleton, county surveyor, December 18, 1840, the first home being built in 1849. In 1895 the citizens of what was then Freedom decided to incorporate, to facilitate improvements to the nascent town's infrastructure. Due to complaints from the Post Office, there being another town calling itself Freedom in Illinois, they were forced to change the name. Col. Friedrich Franz Karl Hecker, whose farm was near Summerfield, Illinois in adjacent St Clair County, was known to and well respected by the town's inhabitants, and they decided to honor him by naming the town after him.
Hecker is located at (38.305433, -89.994241).
According to the 2010 census, the village has a total area of 0.24 square miles (0.62 km2), all land.
As of the census of 2000, there were 475 people, 188 households, and 134 families residing in the village. The population density was 1,993.8 people per square mile (764.2/km²). There were 201 housing units at an average density of 843.7 per square mile (323.4/km²). The racial makeup of the village was 99.16% White, 0.21% African American, and 0.63% from two or more races. Hispanic or Latino of any race were 0.63% of the population.
There were 188 households out of which 31.9% had children under the age of 18 living with them, 60.1% were married couples living together, 9.6% had a female householder with no husband present, and 28.2% were non-families. 23.4% of all households were made up of individuals and 10.1% had someone living alone who was 65 years of age or older. The average household size was 2.53 and the average family size was 3.02.
In the village the population was spread out with 22.3% under the age of 18, 9.7% from 18 to 24, 31.2% from 25 to 44, 23.6% from 45 to 64, and 13.3% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 106.5 males. For every 100 females age 18 and over, there were 100.5 males.
The median income for a household in the village was $43,333, and the median income for a family was $51,071. Males had a median income of $38,125 versus $21,447 for females. The per capita income for the village was $18,423. About 2.8% of families and 4.7% of the population were below the poverty line, including 10.1% of those under age 18 and none of those age 65 or over.
- Combined History of Randolph, Monroe and Perry Counties, Illinois, J. L. McDonough & Co., Philadelphia, 1883
- "US Gazetteer files: 2010, 2000, and 1990". United States Census Bureau. 2011-02-12. Retrieved 2011-04-23.
- "2010 Census U.S. Gazetteer Files for Places – Illinois". United States Census. Retrieved 2012-10-13.
- "American FactFinder". United States Census Bureau. Retrieved 2008-01-31.