The first significant development and settlement occurred in 1887 when the Missouri Pacific Railroad came through from the east, on its way to Pueblo and Colorado's rich gold fields of the "Pikes Peak Or Bust" Colorado Gold Rush.
The county seat is in Ordway, a town established in 1890 that quickly became the economic hub of the area. Other towns still existing along the Missouri Pacific Railroad's route are Sugar City, Crowley, Olney Springs, and Pultney.
A few years later, developers brought a canal east from the Arkansas River, with ambitious plans to irrigate a million acres (4000 km²) in Kansas; instead, the canal petered out in Crowley County but did irrigate 57,000 acres (230 km²) along its length. This turned early Crowley County into a lush agricultural mecca...at first.
Crowley County also today hosts a state prison. The 2000 census showed 5,518 county residents, of which 1,955 were prisoners, giving Crowley County the highest percentage of incarcerated prisoners of any county in the U.S.
There were 1,358 households out of which 34.50% had children under the age of 18 living with them, 55.10% were married couples living together, 11.00% had a female householder with no husband present, and 29.50% were non-families. 25.70% of all households were made up of individuals and 13.00% had someone living alone who was 65 years of age or older. The average household size was 2.59 and the average family size was 3.12.
In the county the population was spread out with 18.80% under the age of 18, 9.90% from 18 to 24, 39.60% from 25 to 44, 20.80% from 45 to 64, and 10.80% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 205.40 males (this is the highest of any U.S. county/parish in 2000). For every 100 females age 18 and over, there were 240.90 males.
The median income for a household in the county was $26,803, and the median income for a family was $32,162. Males had a median income of $20,813 versus $21,920 for females. The per capita income for the county was $12,836. About 15.20% of families and 18.50% of the population were below the poverty line, including 23.60% of those under age 18 and 13.50% of those age 65 or over.
Census data for Crowley county includes 1,955 prisoners. The prison population is 19.23% Black, and 24.35% Hispanic. Without the prisoners, Crowley County would be 86.72% White, 0.36% Black, and 21.55% Hispanic. As a percentage of its population, Crowley County has more of its Census population in prison than any other county in the country.