It was founded on May 20, 1876 and named after and in honor of the city of Pittsburgh, Pennsylvania. Franklin Playter is credited with being the city's founder, establishing a government from its earlier incarnation as a coal mining camp in the 1870s.
Pittsburg is the home to Pittsburg State University, founded as a normal training institution. It has always had a strong manual and industrial arts program and has trained many of the area's public and private school teachers.
A relic of the city's coal mining days was the Pittsburg & Midway Coal Company, founded in 1885, and one of the oldest continuously running coal companies in the United States (even though its headquarters moved several years ago to Denver, Colorado after the Kansas mines closed). In September 2007, Chevron which owned the company merged it with its Molycorp Inc. coal mining division to form Chevron Mining thus ending the Pittsburg corporate name. Midway referred to a coal camp in eastern Crawford County, Kansas that was "midway" between Baxter Springs, Kansas and Fort Scott, Kansas. Kenneth A. Spencer whose father was among the founders of the company was to play an important role in Kansas and Missouri philanthropy.
As of the census of 2000, there were 19,243 people, 7,980 households, and 4,213 families residing in the city. The population density was 1,546.2 people per square mile (596.8/km²). There were 8,855 housing units at an average density of 711.5/sq mi (274.6/km²). The people are 89.73% White, 3.11% Black/African American, 1.08% Native American, 1.94% Asian, 0.17% Pacific Islander, 1.90% from other races, and 2.08% from two or more races. Hispanic or Latino of any race were 3.75% of the population.
There were 7,980 households out of which 25.1% had children under the age of 18 living with them, 38.0% were married couples living together, 11.2% had a female householder with no husband present, and 47.2% were non-families. 34.5% of all households were made up of individuals and 12.7% had someone living alone who was 65 years of age or older. The average household size was 2.23 and the average family size was 2.91.
In the city the population was spread out with 20.8% under the age of 18, 24.1% from 18 to 24, 24.1% from 25 to 44, 16.8% from 45 to 64, and 14.1% who were 65 years of age or older. The median age was 28 years. For every 100 females there were 94.1 males. For every 100 females age 18 and over, there were 92.0 males.
The median income for a household in the city was $24,221, and the median income for a family was $36,674. Males had a median income of $26,312 versus $20,132 for females. The per capita income for the city was $15,318. About 13.6% of families and 22.5% of the population were below the poverty line, including 24.2% of those under age 18 and 10.3% of those age 65 or over.