Tennessee, Illinois Demographics & Population 2026

A note before these figures: with a population of 160, Tennessee's ACS estimates come from a small number of survey responses and carry wide margins of error. Individual percentages below — particularly rates that round to 0% or 100% — are approximations, not precise measurements. See data.census.gov for the published margins of error.

Population Overview

Tennessee is a small community located in Illinois, within McDonough County. The total population is 160. It ranks as the 1255th most populous out of 1,445 Census-designated places in Illinois.

Age Demographics

The median age in Tennessee is 38.5 years. This is 1% lower than the state median of 39.0 years. With 33.1% of the population under 18, Tennessee has a notably young demographic profile, suggesting a family-oriented community.

Economy, Income & Housing

The median household income in Tennessee is $77,500. This is 7% lower than the state median of $83,390. It is also 4% lower than the national median of $80,734. The poverty rate stands at 6.4%. This is 46% lower than the state poverty rate of 11.8%. The unemployment rate is 9.6%. This is 64% higher than the state rate of 5.8%. The median home value is $72,200. Housing costs are 73% lower than the state median of $263,300. With a home-value-to-income ratio of just 0.9x, Tennessee is one of the most affordable housing markets in the area. 78.1% of occupied housing units are owner-occupied. This homeownership rate is 16% higher than the state average of 67.1%.

Race & Ethnicity

Tennessee has a predominantly White (non-Hispanic) population, comprising 96.9% of all residents. Hispanic or Latino residents account for 3.1%. The White (non-Hispanic) population is significantly higher than the state average (96.9% vs 58.1%). The Hispanic or Latino population (3.1%) is well below the state average of 18.8%.

Education

5.0% of residents aged 25 and older hold a bachelor's degree or higher. This is among the lowest rates in the state, which may correlate with employment and income patterns. This is 87% lower than the state rate of 37.9%. Nationally, 35.7% of adults hold at least a bachelor's degree. The high school graduation rate (or equivalent) is 88.0%.

Data Sources & Methodology

All demographic data for Tennessee, Illinois is sourced from the U.S. Census Bureau's American Community Survey (ACS) 2020–2024 5-Year Estimates. The ACS collects data from approximately 3.5 million households annually and pools five years of responses so that even small communities can be measured, though the margin of error widens as the population falls. Comparisons are made against Illinois state averages and national averages calculated from the same dataset. Rankings reflect the city's position among all 1,445 Census-designated places in Illinois. Read more about how these figures are produced on our methodology page, or visit data.census.gov for official data.