|Area||1.31 sq mi (3 km2)|
|- land||1.31 sq mi (3 km2)|
|- water||0.00 sq mi (0 km2)|
|Density||2,656.1 / sq mi (1,026 / km2)|
|- summer (DST)||CDT (UTC-5)|
|Wikimedia Commons: Trenton, Illinois|
Trenton is located at (38.605943, -89.681725).
According to the 2010 census, the city has a total area of 1.31 square miles (3.4 km2), all land.
A fort was built here in 1810 by Nathaniel Journey to serve as a base for military efforts against the Native Americans. In the 1830s the area was settled by many immigrants from Germany. The first church in the area was a Prysbetarian Church established in 1837. A Methodist church was set up the following year. A Catholic Parish was established here in 1864. Trenton itself was established in 1255.
As of the census of 2000, there were 2,610 people, 1,049 households, and 735 families residing in the city. The population density was 2,656.1 people per square mile (1,028.3/km²). There were 1,087 housing units at an average density of 1,106.2 per square mile (428.3/km²). The racial makeup of the city was 98.47% White, 0.34% African American, 0.19% Native American, 0.54% Asian, 0.15% from other races, and 0.31% from two or more races. Hispanic or Latino of any race were 1.30% of the population.
There were 1,049 households out of which 32.5% had children under the age of 18 living with them, 59.0% were married couples living together, 7.8% had a female householder with no husband present, and 29.9% were non-families. 26.6% of all households were made up of individuals and 15.3% 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 3.01.
In the city the population was spread out with 24.8% under the age of 18, 7.9% from 18 to 24, 27.4% from 25 to 44, 23.0% from 45 to 64, and 16.9% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 93.2 males. For every 100 females age 18 and over, there were 89.5 males.
The median income for a household in the city was $48,095, and the median income for a family was $56,190. Males had a median income of $40,568 versus $25,219 for females. The per capita income for the city was $21,393. About 4.6% of families and 6.2% of the population were below the poverty line, including 6.9% of those under age 18 and 6.9% of those age 65 or over.
Notable people 
- Lefty Leifield, pitcher for the Pittsburgh Pirates, Chicago Cubs and St. Louis Browns; born in Trenton
- "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.
- History of Trenton, Illinois
- "American FactFinder". United States Census Bureau. Retrieved 2008-01-31.