Quinn said yesterday that the legislation is meant to help close a $15 billion budget deficit that threatens to cripple state government.
But what does the legislation mean for Illinois citizens?
Individuals will now pay 5 percent instead of 3 percent and the corporate rate jumps from 4.8 percent to 7 percent.
The full increase is supposed to last just four years. After that, the rates will fall, but not all the way back to their original level.