The three member districts were removed by an amendment to the Illinois Constitution of 1970 promoted by Pat Quinn. The Cutback Amendment was sold to the voters by the empty promise of saving on legislative salaries and promoting efficiency.
It was an absolute failure as the remaining legislators raised their salaries and many of the political hacks survived while the better legislators were out of office once the 1/3 reduction in legislators took effect in 1982.
Yes, now I remember that.