Preemption, Illinois Demographics & Population 2026

A note before these figures: with a population of 127, Preemption'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

Preemption is a small community located in Illinois, within Mercer County. The total population is 127. It ranks as the 1301st most populous out of 1,445 Census-designated places in Illinois.

Age Demographics

The median age in Preemption is 42.0 years. This is 8% higher than the state median of 39.0 years. With 35.4% of the population under 18, Preemption has a notably young demographic profile, suggesting a family-oriented community. 17.3% of residents are 75 or older, suggesting a significant retirement-age population with implications for healthcare services and senior housing.

Economy, Income & Housing

The median household income in Preemption is $86,406. This is 4% higher than the state median of $83,390. It is also 7% higher than the national median of $80,734. The ACS records no residents below the poverty line in Preemption. In a community this small the estimate rests on very few survey responses, so it should be read as an absence of measurement rather than a measured absence of poverty. The survey records no unemployed residents in Preemption, which reflects the size of the sample rather than a labor market without joblessness. The median home value is $110,900. Housing costs are 58% lower than the state median of $263,300. With a home-value-to-income ratio of just 1.3x, Preemption is one of the most affordable housing markets in the area. 100.0% of occupied housing units are owner-occupied. This homeownership rate is 49% higher than the state average of 67.1%.

Race & Ethnicity

The largest racial or ethnic group in Preemption is White (non-Hispanic), making up 84.3% of the population.

Education

21.9% of residents aged 25 and older hold a bachelor's degree or higher. This is 42% lower than the state rate of 37.9%. Nationally, 35.7% of adults hold at least a bachelor's degree. No surveyed resident aged 25 or older reported leaving school before earning a high school diploma, though a rate of exactly 100% reflects the limits of a small sample.

Data Sources & Methodology

All demographic data for Preemption, 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.