Question: When did drinking age changed to 21 in illinois?
Disambiguated questions and answers: question: When did drinking age changed to 21 in illinois for the first time?
When did drinking age changed to 21 in illinois for the second time time?
answer: 1961
1980
Natural Questions answer: 1961
1980 (from the Wikipedia article "U.S. history of alcohol minimum purchase age by state")