Rockbridge, Illinois Demographics & Population 2026

A note before these figures: with a population of 146, Rockbridge'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

Rockbridge is a small community located in Illinois, within Greene County. The total population is 146. It ranks as the 1276th most populous out of 1,445 Census-designated places in Illinois.

Age Demographics

The median age in Rockbridge is 46.5 years. This is 19% higher than the state median of 39.0 years. With 29.4% of the population under 18, Rockbridge has a notably young demographic profile, suggesting a family-oriented community.

Economy, Income & Housing

The median household income in Rockbridge is $98,125. This is 18% higher than the state median of $83,390. It is also 22% higher than the national median of $80,734. The poverty rate stands at 6.9%. This is 42% lower than the state poverty rate of 11.8%. The unemployment rate is 5.4%. This is 8% lower than the state rate of 5.8%. The median home value is $77,500. Housing costs are 71% lower than the state median of $263,300. With a home-value-to-income ratio of just 0.8x, Rockbridge is one of the most affordable housing markets in the area. 90.9% of occupied housing units are owner-occupied. This homeownership rate is 36% higher than the state average of 67.1%.

Race & Ethnicity

The largest racial or ethnic group in Rockbridge is White (non-Hispanic), making up 67.1% of the population. Black or African American residents account for 28.1%. The Black or African American population is significantly higher than the state average (28.1% vs 13.3%). The Hispanic or Latino population (2.1%) is well below the state average of 18.8%.

Education

0.0% 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. Nationally, 35.7% of adults hold at least a bachelor's degree. The high school graduation rate (or equivalent) is 99.0%.

Data Sources & Methodology

All demographic data for Rockbridge, 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.