Sorry to dig up an old thread but being that Bloomington, IL is down the road from me I can say with near certainty that the picture is from the Bloomers.
Take a look at this..
http://alplm-cdi.com/chroniclingilli...ems/show/21201
and
http://alplm-cdi.com/chroniclingilli...ems/show/21190
If you want more info on the picture I'd contact the McLean County Historical Society. They're pretty good at piecing together the history of the area.
Beautiful postcard BTW..