Unit One in Allen Hall?
The Greek system at UIUC is quite large - it used to be massive, and the largest in the country (both in terms of absolute participant numbers as well as the discrete number of Sororities and Fraternities) so as a percentage of total students it was a major aspect.
In the past 30+ years, it no longer makes up nearly the percentage of total students it once did - however, the total student enrollment has also grown.
Then you look at the increase in international students, many of which do not go thru the greek system, and if we back of the napkin math it, while the absolute percentage of students at UIUC who participate in Greek life has dropped the total number has not dropped as precipitously proportionally.
So it’s not surprising that it seems a large number of Instagram affirmation seekers are in greek life there.
As far as;
So the state of Illinois is predominantly “Chicagoland” population and then the rest of the state.
The entire state of Illinois is around 12.8-13 Million people.
The greater Chicagoland Metro Area has around 9.5-10M (of which Illinois residents are likely around 8 - 8.5 M+)
Thus around 65% +/- of Illinois residents are in the Metro of the City.
Also, for the most part unlike many other states, Illinois doesn’t split out their main flagship(s).
You have UIUC. And then there are all the directional Illinois public schools (Northern, Southern, Eastern, Western).
So yes, while there are going to be farm kids, kids from Carbondale, Rockford at UIUC, percentages indicate that a larger majority (supermajority) of students who aren’t internationals or OOS are going to ID as Chicago / Suburban, and the competitive nature of getting in probably means there will be more clusters of kids coming from the Private Schools, Gold Coast Schools, and then the magnet / presidential schools of excellence in the massive suburban sprawl.