The primary topic of this paper is the evolution of the early oxidation catalysts of the 1960's to present-day sophisticated three-way catalysts. Early catalyst formulations are described, along with the chemistry of catalytic emission control for automobiles. The evolution in catalyst formulations and engine control strategy is discussed at length. Precious metal supply and world emission regulations are discussed briefly. The scope of this paper is primarily limited to the U.S. automotive industry and the U.S. standards.