Quincy is a city located in Adams County Illinois. It is also the county seat of Adams County. With a 2020 population of 39,229, it is the 46th largest city in Illinois and the 1141st largest city in the United States. Quincy is currently declining at a rate of -0.30% annually and its population has decreased by -2.20% since the most recent census, which recorded a population of 40,111 in 2020. Spanning over 16 miles, Quincy has a population density of 2,497 people per square mile.
The average household income in Quincy is $65,733 with a poverty rate of 15.32%. The median rental costs in recent years comes to $688 per month, and the median house value is $118,800. The median age in Quincy is 40.7 years, 39.2 years for males, and 42.1 years for females.
According to the most recent ACS, the racial composition of Quincywas:
2021 and 2022 population is estimated by projecting the 2019 numbers.
Rate of Home Ownership
Average Family Size
Average Household Size
The highest rate of high school graduation is among islander people with a rate of 100.00%.
The highest rate of bachelors degrees is among other race people with a rate of 60.76%.
97.18% of Quincy residents speak only English, while 2.82% speak other languages. The non-English language spoken by the largest group is Spanish, which is spoken by 1.18% of the population.
Overall Poverty Rate
Male Poverty Rate
Female Poverty Rate
The race most likely to be in poverty in Quincy is Islander, with 100.00% below the poverty level.
The race least likely to be in poverty in Quincy is Other, with NaN% below the poverty level.
The poverty rate among those that worked full-time for the past 12 months was 2.26%. Among those working part-time, it was 15.83%, and for those that did not work, the poverty rate was 27.20%.
Number of Veterans
Veteran Poverty Rate
Veteran Disability Rate
Labor Force Participation
Non citizens include legal permanent residents (green card holders), international students, temporary workers, humanitarian migrants, and illegal immigrants.
Born in Quincy
98.56% of Quincy residents were born in the United States, with 74.77% having been born in Illinois. 0.31% of residents are not US citizens. Of those not born in the United States, the largest percentage are from Latin America.