Early settlers to the area came in about 1870. Most of the pioneer homes were rough dugouts and sod houses that barely protected their inhabitants from the severe weather often experienced in Kansas. They were fitted with holes in the wall to defend against the Indians. Early settlers killed buffalo to provide food for their family; plus they sent the tanned hides to the east for a cash income. A few settlers tried farming but were unsuccessful because the buffalo tramped down the crops. The first settlement in Great Bend township were made by E. J. Dodge and D. N. Heiser in 1871.
The town was named after the Great Bend of the Arkansas River, a feature noted as early as the first days of the Santa Fe Trail. It was here that a trading post was established and later a small military post, Fort Zarah. After the Civil War the land began to be developed by easterners, and by the early 1870s a town had formed and Great Bend participated for a short time as a cow town, complete with shoot outs, Texas cowboys and saloons. Following the close of the cow town phase, Great Bend took up its place as a regional trade and service center, a role that grew stronger during the growth of the oil industry and, later, when it served as a major World War II Army Air Corps training base. Since then the community has continued to develop as a medical, legal and technical service center, as well as a regional shopping and entertainment provider. Since 1973, the Fuller Brush Company has had its factories here, having moved here from Connecticut after the founder's death.
Great Bend's population was estimated to be in the year , .
As of the census of 2000, there were 15,345 people, 6,371 households, and 4,000 families residing in the city. The population density was 1,443.7 people per square mile (557.4/km²). There were 7,080 housing units at an average density of 666.1/sq mi (257.2/km²). The racial makeup of the city was 89.81% White, 1.62% African American, 0.43% Native American, 0.31% Asian, 0.01% Pacific Islander, 5.77% from other races, and 2.05% from two or more races. Hispanic or Latino of any race were 13.20% of the population.
There were 6,371 households out of which 30.4% had children under the age of 18 living with them, 51.1% were married couples living together, 8.4% had a female householder with no husband present, and 37.2% were non-families. 32.8% of all households were made up of individuals and 15.2% had someone living alone who was 65 years of age or older. The average household size was 2.35 and the average family size was 3.00.
In the city the population was spread out with 25.7% under the age of 18, 9.4% from 18 to 24, 25.4% from 25 to 44, 20.9% from 45 to 64, and 18.7% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 92.3 males. For every 100 females age 18 and over, there were 87.7 males.
The median income for a household in the city was $30,841, and the median income for a family was $38,708. Males had a median income of $29,339 versus $19,647 for females. The per capita income for the city was $17,085. About 11.5% of families and 15.2% of the population were below the poverty line, including 22.0% of those under age 18 and 9.7% of those age 65 or over.