Legal Question in Landlord & Tenant Law in Illinois

Yes it is. Some landlords get a judgment for the sole purpose of putting them legally back into possession of the apartment even after a tenant has already moved out, since some fear the tenant may return. Yes it is a credit ding. If you had legitimate reasons for non-payment and/or moving out, you had the right under Illinois law to make that known, including defending the eviction case. Having ignored it, apparently, you may have some issues renting elsewhere with an order of possession (and possibly a rent judgment) on your credit report. You may be able to explain it to the next landlord, but there's no telling if anyone will believe you. If you still have time to vacate the judgment (normally 30 days but sometimes up to 90 after entry) you MAY be able still to have your day in court and have the judgment lifted. See an attorney. Now.