During the 1800s the city was a stop on the Underground Railroad. It also sheltered hundreds of Mormons during their exile from Missouri. Today, Quincy is a thriving mid-sized industrial city that prides itself on its German heritage as well as its artistic expressions.
As of the census of 2000, there were 40,366 people, 16,546 households, and 10,109 families residing in the city. The population density was 2,761.2 people per square mile (1,066.0/km²). There were 18,043 housing units at an average density of 1,234.2/sq mi (476.5/km²). The racial makeup of the city was 93.02% White, 4.65% African American, 0.19% Native American, 0.54% Asian, 0.01% Pacific Islander, 0.36% from other races, and 1.22% from two or more races. Hispanic or Latino of any race were 0.94% of the population.
There were 16,546 households out of which 28.6% had children under the age of 18 living with them, 46.3% were married couples living together, 11.6% had a female householder with no husband present, and 38.9% were non-families. 33.7% of all households were made up of individuals and 15.3% had someone living alone who was 65 years of age or older. The average household size was 2.30 and the average family size was 2.94.
In the city the population was spread out with 23.4% under the age of 18, 10.0% from 18 to 24, 25.8% from 25 to 44, 20.9% from 45 to 64, and 19.9% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 88.3 males. For every 100 females age 18 and over, there were 85.3 males.
The median income for a household in the city was $30,956, and the median income for a family was $40,718. Males had a median income of $30,734 versus $20,748 for females. The per capita income for the city was $17,479. About 9.2% of families and 12.2% of the population were below the poverty line, including 15.2% of those under age 18 and 8.3% of those age 65 or over.
Interstate 72 passes just south of Quincy. Its spur route, Interstate 172, passes just east of town. In recent years, the Prairie Crossings Shopping Complex has been a focal point for development in this area. Illinois Route 104 (Broadway) is a main east-west artery from the Mississippi River bridges to Interstate 172. Illinois Route 96 enters the city from the southeast and travels north (through the east side of Quincy) to U.S. Route 24. Illinois Route 57 branches south from U.S. 24 downtown and passes Quincy's Civic Center on its way to Interstate 172 southeast of the city. Illinois 96 also serves as the Great River Road, which follows the path of the Mississippi River. Eastbound U.S. 24 crosses the Mississippi River from Missouri on the Quincy Memorial Bridge, while westbound traffic uses the newer Bayview Bridge. Bayview bridge was constructed in 1986, but was not built as a 4-lane bridge because of budget cuts, as the cable suspension made it unaffordable to build a 4-lane bridge. Other groups claimed that business in the downtown part of Quincy would decline if the Memorial bridge was shut down.
On the Missouri side, U.S. Route 61 carries the Avenue of the Saints, a four-lane highway connecting Saint Louis and the Twin Cities. The Avenue of the Saints gets its name from Saint Louis and Saint Paul, Minnesota.
The Quincy Regional Airport is to Quincy's east, about 5 miles (8 kilometers) outside of the city limits.
Quincy has a public bus line and taxi company.
Quincy is also an Amtrak community with a rail station on the north side of town. It is the terminus of two Amtrak routes, the Illinois Zephyr and the Carl Sandburg. Both trains follow the same track to Chicago's Union Station.
Ongoing projects will improve transportation links with nearby major cities. U.S. Route 36, south of Quincy and multiplexed with Interstate 72, is currently (as of August, 2007) being upgraded to a 4-lane highway, which will connect Quincy with Saint Joseph, Missouri and Kansas City, Missouri. With the continuing improvements to Illinois Route 336 north of the city, Quincy will also have a direct connection to Peoria in 2009.