[4] A post office called Black Jack was established in 1872, and operated until 1906.

[5] The community was named for a grove of blackjack oak trees near the original town site.

27.2% of all households were made up of individuals, and 10.6% had someone living alone who was 65 years of age or older.

23.2% of all households were made up of individuals, and 8.2% had someone living alone who was 65 years of age or older.

In May 2006, the Black Jack city government made a controversial decision to remove an unmarried couple and their children from their own home on the grounds that the couple was not related enough to each other to satisfy a municipal ordinance.

For the purpose of obtaining an occupancy permit, Black Jack defined a family as: Therefore, an unmarried couple with one child would qualify as a family, whereas an unmarried couple with multiple children would not.

On August 15 the Black Jack city council unanimously passed a resolution changing the definition of family to include an unmarried couple and their children.