Jackson County was created on January 1, 1816, and was formed from Clark, Jefferson, and Washington counties. Jackson County was the 14th to be organized in the Territory of Indiana. The legislative act forming the county was passed December 18, 1815. The county was named for Andrew Jackson, who defeated the British at the Battle of New Orleans in the War of 1812, and later became president.
The county seat is Brownstown. Brownstown wasn't always the county seat. The first county seat was established at Vallonia in June of 1816. The first courts were held in the shade of the old fort in the village.
Brownstown established and became the county seat November 1816. By 1849, it contained a court house, county seminary, and public offices of brick, as well as 70 dwelling houses and a population of 400. The first settlers were A. C. Craig, Charles Crabb, William Williams, William Congleton, William Crenshaw, John Milroy, and John Ketcham.
For more information and historical details, see county history.