Hamilton County (county code HM) is a county located in the U.S. state of Kansas. As of the 2010 census, the county population was 2,690. Its county seat and most populous city is Syracuse. The county was founded in 1873 and named for Alexander Hamilton.
According to the U.S. Census Bureau, the county has a total area of 998 square miles (2,580 km), of which 997 square miles (2,580 km) is land and 1.1 square miles (2.8 km) (0.1%) is water.
As of the 2000 census, there were 2,670 people, 1,054 households, and 715 families residing in the county. The population density was 3 people per square mile (1/km²). There were 1,211 housing units at an average density of 1 per square mile (0/km²). The racial makeup of the county was 81.65% White, 0.56% Asian, 0.49% Black or African American, 0.49% Native American, 15.13% from other races, and 1.69% from two or more races. Hispanic or Latino of any race were 20.60% of the population.
There were 1,054 households out of which 33.90% had children under the age of 18 living with them, 56.90% were married couples living together, 7.60% had a female householder with no husband present, and 32.10% were non-families. 29.40% of all households were made up of individuals and 15.80% had someone living alone who was 65 years of age or older. The average household size was 2.49 and the average family size was 3.09.
In the county, the population was spread out with 28.40% under the age of 18, 7.20% from 18 to 24, 25.30% from 25 to 44, 20.90% from 45 to 64, and 18.40% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 97.60 males. For every 100 females age 18 and over, there were 92.60 males.
The median income for a household in the county was $32,033, and the median income for a family was $38,550. Males had a median income of $26,701 versus $21,000 for females. The per capita income for the county was $16,484. About 10.90% of families and 15.70% of the population were below the poverty line, including 21.50% of those under age 18 and 9.40% of those age 65 or over.