File:PostcardBloomingtonILEaSideSq1910.jpg
Description: Caption: "Northwest from East Side Square, Bloomington, Ill." Also on front: "1889 S. H. Knox & Co." The "1889" is almost certainly a catalog number, as is seen on many other postcards from the same era. Store Web page states, "postcard, used, postmarked Hudson, Ill. 1910, has a little soiling along the top"
Source: eBay store Web page
The postcard states that this picture is 1889.
I believe this may be correct, as there was a fire that burned down much of the old downtown in about 1900. Perhaps this was the architect's rendering of the new plans?