The confluence of the Mississippi and Missouri Rivers supported some of the earliest settlements in America.  From the Cahokia Mounds civilization to the flood of 1993, residents of the St. Louis region have depended on this landscape even as they have threatened its bounty. In Common Fields , thirteen original essays tell of the city's constant tension between urban growth and environmental sustainability.  Geographers, archaeologists, and historians examine the relationship between the city's diverse residents and the environment on which their well-being depends.  Whether channeling the river, laying streets, or clearing the air of coal smoke, St. Louisans have shown great ingenuity in overcoming the hazards of city development. And yet, our solutions to making the best use of the environment have only highlighted more basic societal questions:  How do we ensure liberty while providing equal opportunities?  How do we recognize uniqueness while eliminating barriers that prevent others' success?  The answers have everything to do with our ability to make sensible use of our environment-just as the rivers, fields, and city streets will forever shape the character of this city.