20 ILCS 835/4b: Products manufactured in the United States.

Gift shops and concession areas within State parks and parkways shall set aside a booth or section for the sale of products manufactured in the United States. As used in this Section, "products manufactured in the United States" means assembled articles, materials, or supplies for which design, final assembly, processing, packaging, testing, or other process that adds value, quality, or reliability occurred in the United States.