[2] The county was formed on December 21, 1837, and named after US President Andrew Jackson.

[3] In the early morning of July 22, 2022, an assailant killed three members of a family at the campground of Maquoketa Caves State Park, located in the county.

The assailant, identified as 23-year-old Anthony Sherwin of Nebraska, later committed suicide.

[12] As of the census[13] of 2000, there were 20,296 people, 8,078 households, and 5,589 families residing in the county.

27.00% of all households were made up of individuals, and 13.80% had someone living alone who was 65 years of age or older.

As of 2018[update] the three-member Jackson County Board of Supervisors is Larry McDevitt, Mike Steines, and Jack Willey.

The towns of Maquoketa, Preston, Miles, Springbrook, Sabula, Baldwin, Bellevue, Andrew and La Motte all have their own fire departments providing protection for the whole county.

Mutual Aid Agreements from surrounding Iowa counties as well as the state of Illinois are in place to provide additional help during emergencies which tax the county emergency resources beyond their limits.

The county was reliably Democratic from 1988 to 2012, but swung by 18% to back Donald Trump in 2016.

In 2020 Donald Trump carried Jackson County with 62% of the vote over Joseph Biden's 36%.