Johnson received a kidney from his 25-year-old son Daniel. A hospital spokesperson said surgeries on both Johnson and his son went smoothly and as expected. Johnson in now listed in fair condition, and is conscious with stable vital signs. His son is listed in good condition.
The operations were performed by Dr. Martin Hertl and Dr. Edward Hollinger and their surgical teams, the hospital said. They will provide another update Thursday at 11 a.m.
The 57-year-old superintendent said he's been waiting 31 years to feel better. He also emphasized the attention on his surgery isn't just attention on himself, but the importance of organ donation overall. Kimberly Gosell understands that importance intimately.
"Every day that I have been given is a day I didn't expect to get," she said.
Gosell got a kidney transplant in 2009 from a cousin, and almost died four times before receiving a second kidney transplant from her father in 2014. Earlier this year she met Johnson.
"On the other side of this is just an amazing reward and a wonderful life for him, so I'm excited," she said.
Johnson's private medical issues became public back in January, when he fainted during a press conference and it was caught on camera. The superintendent said that experience has encouraged others to visit doctors and seek treatment if they think they have the same issue.
When it was clear Johnson's kidneys were failing, his son, Daniel, stepped forward and offered to be a living donor. If his son hadn't offered his kidney, it would've been a long wait. The national waiting list is 100,000 deep. On average, it takes five years before there's a match.
Johnson arrived at Rush University Medical Center around 6:10 a.m. and spoke to the press. He said he's feeling great, but is anxious to a complete the procedure.
"I just really want to thank the citizens of Chicago. The support my son and I have gotten is unexpected and overwhelming. I really don't think that Webster's Dictionary has the word in there yet, that really can describe that feeling. So, thank you," Johnson said.
He said he's proud of his son for stepping up, for choosing to donate and for helping raise more awareness about how many lives can be saved through organ donation.
"I'll tell you this. The whole journey, to this point, is not about Eddie Johnson. It's about shining a spotlight on organ donation, period. But I'm proud of him because it's a decision that he made on his own. It's humbling, because it's not an easy thing, I'm sure, to make that decision. But it just highlights how important it is for people to do organ donation," Johnson said.
Johnson was put on an intense exercise routine since the transplant was scheduled, to prepare his body for surgery and recovery. He said he's been doing about 40 minutes of cardio a day and has been eating healthier. He said he's lost about 50 pounds since Feb. 1, and it feels good.
"The difference between how I feel physically today as compared to this time last year is like night and day," Johnson said.
He'll spend three to five days in the hospital after surgery and three to six weeks at home to recover.
"I wish my good friend Eddie Johnson and his son Daniel successful transplant surgeries and speedy recoveries," said Illinois Secretary of State Jesse White, the head of the state's organ/tissue donor registry. "I applaud the superintendent for being a strong advocate for organ and tissue donation and I consider Daniel a hero for donating a kidney to his father."
WATCH: Doctor explains kidney transplant surgery