Lt. Keith Immerfall walks past prison cells at Waupun Correctional Institution, a maximum security prison in Waupun, Wis. If the more than 1,200 prisoners at the facility are still incarcerated there on April 1, the next Census Day, the Census Bureau will officially consider them residents of Waupun for the 2020 national head count.

Lt. Keith Immerfall walks past prison cells at Waupun Correctional Institution, a maximum security prison in Waupun, Wis. If the more than 1,200 prisoners at the facility are still incarcerated there on April 1, the next Census Day, the Census Bureau will officially consider them residents of Waupun for the 2020 national head count.