For millennia, microorganisms, fungi, plants, and animals have struggled within their physical environment to produce balanced, climax grasslands. Within a mere 50 years or so of first trekking across seemingly endless oceans of prairie (520,000 km 2 or 200,000 sq. mi.), American settlers converted most of these fertile, native grasslands into farmland. This became our nation's "breadbasket" and cereal grains, which are grass seeds, became one of the most important foods grown on the deep, rich soils of the Midwest. Wheat, corn, oats, barley, rice, sugar cane, sorghum, and millet are all used for human or livestock consumption. Grains became important foods to people perhaps as early as 9,000 years ago. Different cultures around the world developed various grains, such as wheat in the Middle East and corn in Mexico.

Even though people do not digest cellulose, the fabric of grass, we depend on seeds, or grains, for starch (a carbohydrate) and oil. But very little of a grass plant goes to waste. Stalks are used as straw to make many products such as brooms and baskets, or are harvested as hay for fodder. Because grasses are so important, so are the grasslands from which they come.