Authorities are trying to figure out how and why the boy was out alone at night.
He has been in the care of DCFS since he was found.
At this point, police are interviewing the mother. She has not been charged with anything but it is a possibility.
Authorities believe he is 3 or 4 years old.
He weighs 35 pounds and is three feet tall, police said.
He was found wearing a black hooded, down coat and a black knit cap with the word "Obama" on it, according to authorities.
He was also wearing a Nike hoodie, blue jeans and black and white Adidas gym shoes, police said.