Military medals groups like this peace time pre WWI group can be very helpful especially when they contain generic awards like the armory marksmanship award in the center below the ribbon bars.  By itself this award would be impossible to attribute to a state of issue since there is no state name or emblem anywhere in the design. However in this case since the group is obviously from Illinois therefore the mystery medal is also. The only remaining question would be did any other states use the same design?