Almost every year, the state of Illinois ranks fourth behind the "Big Three" of Florida, Texas, and California in the number of players that are drafted. Granted that is only one northern state but it shows that there is talent.
I agree with the previous posts that say that Illinois kids seem to want it a bit more when they come to southern schools. The northern kids I know who play in the south all are praised by their coaches for their level of committment and work habits. Sometimes those from the south take for granted the fact that it is 60 degrees in March.