Native American gardeners domesticated a variety of native plants, producing surplus food and storing it for later consumption. This new way of life was accompanied by technological advancements such as pottery, more trade, and changes in social organization and religion. By 900 years ago, maize, a tropical grass hybrid from Mexico, was grown in Illinois. Maize production required more labor but yielded more food, both of which sparked population growth and unprecedented changes in every aspect of Native American life. Illinois’ first metropolis, Cahokia, a community of perhaps 20,000 people, commanded the economic, social, and political landscape of the Midwest for nearly three centuries.