This book focuses on how rivers function, how those functions have changed through time, and the role of humans in those changes. A river continually responds to changes in its environment and is never static. The type of river response depends on the magnitude and persistence of changes in water and sediment entering the river. The movements of water and sediment within a sand-bed channel adjust readily over a period of minutes to hours. The book discusses rivers of the Northeast and East-Central region of the United States, which drain east to the Atlantic Ocean. The single largest drainage basin in this region is the St. Lawrence, which delivers an average of 65,000 billion gallons of water to the ocean each year. The book examines the river systems in America, explains how the earliest human inhabitants reached America and modified the physical and biological environments of the rivers, and reveals that sedentary agricultural communities first appeared in the archeological record of North America more than 2,000 years ago. As with agricultural peoples elsewhere in the world, these first farmers affected rivers more than their hunter-gatherer predecessors. The book discusses the impact of industrialization on the health of rivers in United States, also focusing on the restoration and rehabilitation of rivers.