No, however marijuana was recently decriminalized by Governor Bruce Rauner. You are allowed to possess up to 10 grams of cannabis without being given a criminal charge. Essentially if you are caught with less than 10 grams it is equivalent to a traffic ticket. These can be punishable by large fines so I recommend not getting caught because you will have to pay money.
No, the law for marijuana in Illinois is still the same for travelers as it is for the locals. Medical marijuana is only legal for conditions that are qualify under Illinois Medical Marijuana Law. If you have a medical marijuana card from a different state Illinois will not honor out of state cards.
Keep in mind that although considered decriminalized in Illinois, possession of 10 grams or less is still punishable by a citation of up to $200, especially for public consumption. Also know that possessing more than 10 grams in Illinois is still a misdemeanor. Otherwise the same laws apply to you as the locals. Illinois dispensaries do not honor out of state medical cards either.