Brown County (county code BR) is a county located in the northeast portion of the U.S. state of Kansas. As of the 2010 census, the county population was 9,984 with a 2018 estimate of 9,598. Its county seat and most populous city is Hiawatha. Brown County is the location of the Kickapoo Indian Reservation of Kansas, the majority of the Sac and Fox Reservation and the majority of the Iowa Reservation of Kansas and Nebraska.
According to the U.S. Census Bureau, the county has a total area of 572 square miles (1,480 km), of which 571 square miles (1,480 km) is land and 1.2 square miles (3.1 km) (0.2%) is water. The Wolf River has its source in the county. Brown State Fishing Lake, formerly known as “Brown County State Park” is in the county, 8 miles (13 km) east of Hiawatha.
As of the 2000 census, there were 10,724 people, 4,318 households, and 2,949 families residing in the county. The population density was 19 people per square mile (7/km²). There were 4,815 housing units at an average density of 8 per square mile (3/km²). The racial makeup of the county was 86.87% White, 1.56% Black or African American, 8.82% Native American, 0.21% Asian, 0.01% Pacific Islander, 0.73% from other races, and 1.81% from two or more races. Hispanic or Latino of any race were 2.32% of the population.
There were 4,318 households out of which 31.40% had children under the age of 18 living with them, 55.80% were married couples living together, 9.20% had a female householder with no husband present, and 31.70% were non-families. 28.80% of all households were made up of individuals and 15.70% had someone living alone who was 65 years of age or older. The average household size was 2.44 and the average family size was 2.99.
In the county, the population was spread out with 26.40% under the age of 18, 7.40% from 18 to 24, 24.00% from 25 to 44, 22.70% from 45 to 64, and 19.50% who were 65 years of age or older. The median age was 40 years. For every 100 females there were 93.50 males. For every 100 females age 18 and over, there were 89.80 males.
The median income for a household in the county was $31,971, and the median income for a family was $39,525. Males had a median income of $29,163 versus $19,829 for females. The per capita income for the county was $15,163. About 10.60% of families and 12.90% of the population were below the poverty line, including 16.40% of those under age 18 and 11.80% of those age 65 or over.