That should be spelled out in the lease. I've sold a number of properties that had tenants...each of them were sold "subject to tenant's rights" so the new owner had to abide by the terms of the original lease (amount of rent, term of lease, etc.) If no lease is in place, best to contact a local real estate attorney for specific guidance.
If you are living on a month to month lease then I believe the landlord must inform you 30 days prior that you must vacate the property. So if you pay rent on the 1st of the month, the landlord must inform you on or before the first.
There is a clause in Chicago that you may be entitled to 60 day notice, but an attorney would be the best person to contact.