DeKalb County was the one time home of the famous Cherokee Sequoyah.
The county's eastern edge, along the state line, was also the epicenter of a strong earthquake on 2003 April 29, measuring 4.6 on the Richter scale. Power was knocked out in the area, mirrors and pictures thrown to the floor, foundations cracked, and one chimney fell to the ground. It was felt over a significant portion of the southeastern states, including quite strongly in northeastern Alabama and neighboring northwestern Georgia, and nearby eastern Tennessee (especially near Chattanooga). It was also felt slightly in western upstate South Carolina, far west-southwestern North Carolina, south and southeastern Kentucky, and east-northeastern Mississippi.
(See: 2003 Alabama earthquake)
There were 25,113 households out of which 33.20% had children under the age of 18 living with them, 59.50% were married couples living together, 9.90% had a female householder with no husband present, and 26.60% were non-families. 23.80% of all households were made up of individuals and 10.80% had someone living alone who was 65 years of age or older. The average household size was 2.53 and the average family size was 2.98.
In the county the population was spread out with 24.70% under the age of 18, 9.20% from 18 to 24, 29.10% from 25 to 44, 23.20% from 45 to 64, and 13.80% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 95.60 males. For every 100 females age 18 and over, there were 92.50 males.
The median income for a household in the county was $30,137, and the median income for a family was $35,801. Males had a median income of $28,878 versus $19,103 for females. The per capita income for the county was $15,818. About 11.70% of families and 15.40% of the population were below the poverty line, including 18.60% of those under age 18 and 20.50% of those age 65 or over.