In Illinois, the statute of limitations is 2 years in most personal injury cases. However, there are shorter 1 year statutes for certain defendants. Municipalities, for example.
Further, minors with injuries from accidents typically have 2 years from their 18th birthday to file a lawsuit against most defendants. But again, there are shorter exceptions.
You must file your lawsuit within the statute of limitations. Otherwise, the plaintiff will be time barred from pursuing the case and recovering any damages.
Finally, do not wait until the last minute to try to find an attorney. Most lawyers will not take a case that is too close to the statute of limitations.