(CNN) -- The Illinois Senate approved the use of marijuana for medical purposes on Friday, sending the measure to the governor's desk.
The move by Illinois lawmakers came the same day that Ohio's attorney general certified a petition for a proposed amendment that would allow marijuana be used for industrial, medical and therapeutic purposes.
If approved, Illinois and Ohio would join 19 states and the District of Columbia that have some variation of a medical marijuana law.
Under the approved law in Illinois, a four-year trial would establish 60 dispensing centers across the state and allow doctors to prescribe 2.5 ounces of marijuana to a patient every two weeks.
To be prescribed medical marijuana, patients would need to have one of 42 conditions, including cancer and HIV, according to the legislation. Patients also would undergo background checks.
Gov. Pat Quinn has not indicated whether he will sign the bill.
Meanwhile, Ohio Attorney General Mike DeWine on Friday certified a petition for a proposed amendment allowing for medical marijuana, the first step in an attempt by the Ohio Rights Group to put the issue to a statewide vote in 2014.
"Without passing upon the advisability of the approval or rejection of the measure to be referred, I hereby certify that the summary is a fair and truthful statement of the proposed constitutional amendment," DeWine said in a letter to the Ohio Ballot Board.
CNN's Dave Alsup contributed to this report.