It's not your imagination: you did really see a fireball in the sky over Peoria on Sunday night.
The National Weather Service in Lincoln said sightings of the meteor were reported as far south as Peoria and Champaign around 8:40 p.m. Sunday. Most sightings were concentrated to the west, with the majority in the Kansas City and Omaha areas. There were also numerous reports in the Chicago area.
The American Meteor Society reports more than 270 sightings across the Midwest.