Quincy Flag

Quincy

County:
Adams County
County Seat:
Yes
Area (mi²):
15.767
State:
Illinois

Quincy is a city located in Adams County, Illinois. Quincy has a 2026 population of 38,740. It is also the county seat of Adams County. Quincy is currently declining at a rate of -0.46% annually and its population has decreased by -2.08% since the most recent census, which recorded a population of 39,564 in 2020.

The median household income in Quincy is $56,480 with a poverty rate of 16.69%. The median age in Quincy is 39.7 years: 38.4 years for males, and 40.9 years for females. For every 100 females there are 96.2 males.

38.7K
Total Population
2,457
Density (mi²)
-178 -0.46%
Growth

Quincy Population

Quincy Population

Year ↓
Population
Growth
Annual Change
202638,740-178-0.46%
202538,918650.17%
202438,853-146-0.37%
202338,999130.03%
202238,986-324-0.82%
202139,310-254-0.64%
202039,564-57-0.14%
201939,936-107-0.27%
201840,043-247-0.61%
201740,290-218-0.54%
201640,508-199-0.49%
201540,707-51-0.13%
201440,758-23-0.06%
201340,781-62-0.15%
201240,843-61-0.15%
201140,9041340.33%
201040,7701370.34%
200040,3666851.73%
199039,681-2,873-6.75%
198042,554-2,734-6.04%
197045,2881,4953.41%
196043,7932,3435.65%
195041,4509812.42%
194040,4691,2283.13%
193039,2413,2639.07%
192035,978-609-1.66%
191036,5873350.92%
190036,2524,75815.11%
189031,4944,22615.5%
188027,2683,21613.37%
187024,05210,33475.33%
186013,7186,81698.75%
18506,90200%

Median Age

Overall: 39.7 years
Female: 40.9 years
Male: 38.4 years

Quincy Adults

There are 30,682 adults, (7,928 of whom are seniors) in Quincy.

Sex Ratio

Female: 19,930 (51%)
Male: 19,179 (49%)

Demographics

The racial composition of Quincy includes 86.67% White, 4.24% Black or African American, and smaller percentages for Asian, other race, Native American, Native Hawaiian or Pacific Islander and multiracial populations.

Population by Race

Race
Population ↓
Percentage (of total)
White33,89586.67%
Two or more races2,7897.13%
Black or African American1,6574.24%
Asian4041.03%
Other race3080.79%
Native American470.12%
Native Hawaiian or Pacific Islander90.02%
Race
Population ↓
Percentage (of total)
Two or more races4621.18%
White2640.68%
Other race2110.54%
Native American190.05%
Black or African American130.03%
Race
Population ↓
Percentage (of total)
White33,63185.99%
Two or more races2,3275.95%
Black or African American1,6444.2%
Asian4041.03%
Other race970.25%
Native American280.07%
Native Hawaiian or Pacific Islander90.02%

Quincy Marital Status

Economics and Income Statistics

Quincy's average per capita income is $45,249. Household income levels show a median of $56,480. The poverty rate stands at 16.69%.

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$101,027-
Families$77,984$104,981
Households$56,480$78,604
Non Families$38,742$48,923

$45,249

Average Income

$56,480

Median Household Income

16.69%

Poverty Rate

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)