Answer: Blackberries bear fruit on second year canes, so to have fruit this year there should be some second year canes that grew last summer but did not yet bear fruit. You should also see new growth coming up from the ground each spring, these canes will not bear their first year but will bear their second year. The canes that bore fruit last year are finished and should be pruned off.
Based on your description I am not certain what is happening to your blackberries, perhaps you planted a variety that is not reliably hardy in your area. Generally speaking, the variety "Illini Hardy" would probably be the most reliable in northern Illinois but it is not a sure thing.
You might want to check with your retailer and/or county extension and see what varieties (if any) they specifically recommend for your local area and when to expect to see new growth, based on the weather this year.
Here is some general information on growing and training brambles you may find helpful. You might want to try raspberries rather than blackberries as they are more winter hardy.
I hope this helps.
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