jackson county (county code ja) is a county in the u.s. state of kansas. in 2010, 13,462 people lived there. its county seat is holton. holton is also the biggest city in jackson county. the county was first named calhoun county. this was named after pro-slavery south carolina senator john c. calhoun. the county was renamed in 1859 for president andrew jackson. the prairie band potawatomi indian reservation is in the county, and it makes up about 18.5% of the county's area.