It took thousands of years for the prairie to be created. Only the plants that could adjust to warmer climate changes and changes in rainfall, drainage, soil type and land form could survive. The prairies are made up of grasses and many flowers that help to make up the 300 species of plants native to Illinois. To protect themselves from the sun and heat from fire, the prairie plants developed a deep root system in order to reach water. Trees were unable to replace the prairie grass due to the thick roots and the coming of men with plows.
Native Americans and early settlers found many uses for prairie plants, such as food, medicine, housing needs, clothing, paper, perfume and dyes.