Gov. Pat Quinn has five days to determine when he'll set a special election to replace Congressman Jesse Jackson Jr.
Jackson resigned Wednesday. Quinn was informed in the afternoon.
The governor says that the election will be carried out in a manner that's as fair and economical as possible for taxpayers.
Election law says it must be held within 115 days.
Quinn says there will likely be a primary and a general election for voters in Chicago's 2nd Congressional District. The territory includes neighborhoods on Chicago's South Side and south suburbs.
Jackson has been on medical leave for months. He's also under a federal investigation and had been under a U.S. House Ethics Committee probe.
Quinn says his thoughts and prayers are with Jackson and his family.