Since 1948, the federal government has assumed an increasingly dominant role in efforts to control pollution of surface waters in the United States. Over that half century, the federal role has evolved from research support and financial grants to states, to federal effluent standards and a national permit requirement, and, more recently, to enforcement of a mandate to achieve water quality standards. This Article describes the evolution of federal water pollution control legislation in the United States. It focuses particularly on the 1972 statute prescribing feasibility-based controls for point sources and its 1977 modification, the increasing concern with toxic pollution in the 1980s, and recent litigation requiring total maximum daily loads for waters that fail to meet water quality standards. The Article then examines this description to evaluate the accomplishments and failures of each step in the legislative evolution, and to extract practical lessons so that future water pollution control legislation may be successful.