11,552 people (2024 Census estimate, −1.3% since 2020)
387 square miles of land · 30 people per square mile
“Highest” and “lowest” are just order, not grades: a high rank for poverty or hazard losses means more of it. Each figure's source is in its section below.
11 active community water systems list Marshall County in the area they serve, reporting 9,179 people served in all (a system that crosses county lines counts its whole population).
| HENRY groundwater · local government · IL1230050 | 2,230 served |
| LACON groundwater · local government · IL1230100 | 1,900 served |
| TOLUCA groundwater · local government · IL1230250 | 1,348 served |
| IL AMERICAN-LAKE WILDWOOD groundwater · private · IL1235200 | 1,295 served |
| WENONA groundwater · local government · IL1234950 | 974 served |
| HOPEWELL groundwater · private · IL1235150 | 420 served |
| SPARLAND groundwater · local government · IL1230200 | 358 served |
| VARNA groundwater · local government · IL1230300 | 342 served |
Source: U.S. EPA Safe Drinking Water Information System (SDWIS), active community systems, . Look up any system's violations and test results with EPA's search using its ID.
About 2 people were held in Marshall County's jail, in Vera's latest figure (2024), or 29 per 100,000 residents ages 15–64. In 2019 it was about 1.
Source: Vera Institute of Justice, Incarceration Trends (built from federal Bureau of Justice Statistics jail surveys). Counties without their own jail, or that share one, may show no figure.
2 school districts have their office in Marshall County. School taxes are usually the largest part of a property tax bill.
Spent $13.4 million — $8.7 million to run schools, about $13,014 per student, plus $3.4 million on buildings and equipment. Money in: $6.5 million local (mostly property tax), $4.4 million state, $1.6 million federal. Long-term debt: $8 million.
Spent $10 million — $9 million to run schools, about $16,766 per student, plus $469,000 on buildings and equipment. Money in: $5.3 million local (mostly property tax), $4.9 million state, $736,000 federal. Long-term debt: $107,000.
Source: U.S. Census Bureau, 2023 Annual Survey of School System Finances. Districts are listed by the county of their main office; some serve neighboring counties too.
Source: County Health Rankings & Roadmaps 2025 (University of Wisconsin Population Health Institute), which gathers federal data (CDC, Census, and others); measures cover different recent years. Blank lines aren't reported for small counties.
Overall risk: Very Low compared with other U.S. counties. FEMA estimates natural hazards cost Marshall County about $8.7 million a year on average in buildings, crops and lives. Ability to bounce back (community resilience): Very High; social vulnerability: Relatively Moderate.
Source: FEMA National Risk Index (December 2025), expected annual loss. Ratings compare counties nationwide; they're estimates, not predictions.
155 bridges in Marshall County: 65 in good condition, 71 fair, and 19 poor (12.3%). “Poor” means a main part — the deck, the beams, or the supports — is rated 4 or lower on the federal 0–9 scale. It doesn't mean unsafe to drive; unsafe bridges are closed.
| ILL 18 over ILL RIVER CROMWELL DR · built 1934 | 2,200 vehicles a day |
| ILL 17 over INTERMITTENT STREAM · built 1971 | 1,150 vehicles a day |
| ILL 117 over SOUTH BR CROW CREEK · built 1932 | 650 vehicles a day |
| FAS 2368 (CH-S51) over SANDY CREEK · built 1969 | 175 vehicles a day |
| FAS 2368 (CH-S51) over JUDD CREEK · built 1969 | 175 vehicles a day |
| ELM STREET over GIMLET CREEK · built 1982 | 100 vehicles a day |
Source: Federal Highway Administration, National Bridge Inventory (2025 submission). Includes state, county and city bridges.
Federal grants paid for $16 million of work in Marshall County in fiscal 2025, about $1,359 per resident — to the county, cities, schools, hospitals, nonprofits and others.
Source: USAspending.gov, grants by place of performance, fiscal 2025 (Oct. 2024 to Sept. 2025). Search it by county to see each award.
From Grants.gov: posted grants listing county governments as eligible, soonest deadline first; research-only and overseas programs left out; list updated 2026-10-13, refreshed weekly. 62 are open in all. Cities, towns, school districts and nonprofits have their own lists there.
Registration deadlines, early voting and polling places for Illinois are on the federal site vote.gov, which links to the state's official election office.
The budget, property tax rates, audits, local officials and offices for Marshall County come from the county's own records, which we haven't gathered — not gathered, never hidden. See what a full county site looks like, or ask to have Marshall County built: brayden.ozark@gmail.com.
More of Illinois: the state government and every county in Illinois.
Nearby counties: Putnam County (12 mi) · Woodford County (18 mi) · Stark County (24 mi) · Bureau County (27 mi) · Peoria County (28 mi) · LaSalle County (32 mi).