Foster township Flag

Foster township

County:
Marion County
County Seat:
No
Area (mi²):
35.557
State:
Illinois

Foster township is located in Marion County, Illinois. Foster township has a 2026 population of 340. Foster township is currently declining at a rate of -1.16% annually and its population has decreased by -6.08% since the most recent census, which recorded a population of 362 in 2020.

The median household income in Foster township is $129,375 with a poverty rate of 2.82%. The median age in Foster township is 34 years: 35.9 years for males, and 28.7 years for females. For every 100 females there are 100.0 males.

340
Total Population
9.6
Density (mi²)
-4 -1.16%
Growth

Foster township Population

Foster township Population

Data after 2023 is projected based on recent change

Year ↓
Population
Growth
Annual Change
2026340-4-1.16%
2025344-4-1.15%
2024348-4-1.14%
2023352-2-0.56%
2022354-5-1.39%
2021359-3-0.83%
2020362-1-0.28%
2019354-2-0.56%
2018356-3-0.84%
2017359-5-1.37%
2016364-3-0.82%
2015367-2-0.54%
2014369-1-0.27%
2013370-5-1.33%
2012375-1-0.27%
2011376-3-0.79%
201037900%

Median Age

Overall: 34 years
Female: 28.7 years
Male: 35.9 years

Foster township Adults

There are 275 adults, (38 of whom are seniors) in Foster township.

Sex Ratio

Female: 195 (50%)
Male: 195 (50%)

Demographics

The racial composition of Foster township includes 100% White, and smaller percentages for and multiracial populations.

Population by Race

Race
Population ↓
Percentage (of total)
White390100%
Race
Population ↓
Percentage (of total)
White390100%

Foster township Marital Status

Economics and Income Statistics

Foster township 's average per capita income is $73,512. Household income levels show a median of $129,375. The poverty rate stands at 2.82%.

Families: A family includes the owner or renter of the home along with everyone related to them - whether through birth, marriage, or adoption. This includes relatives like spouses, children, parents, siblings, grandparents, and any other family members.
Households: A household includes all the people who occupy a housing unit (such as a house or apartment) as their usual place of residence.
Non Families: A nonfamily household is either someone living alone or when the owner/renter lives with people they aren't related to, like roommates.
Name
Median ↓
Mean
Married Families$136,304-
Families$135,788$140,802
Households$129,375$128,194
Non Families$81,058$72,300

$73,512

Average Income

$129,375

Median Household Income

2.82%

Poverty Rate

Nearby Cities

Sources

  1. US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  2. US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
  3. American Community Survey (2009 - 2013)
  4. Census QuickFacts
  5. Historical Populations of States and Counties (1790 - 1990)