The purpose of this paper is to provide an overview of the history, development, and services of the packet switching network services that currently exist in the United States. The character of packet switching, a computerized method of transmitting data, is used as the basis for tracing the development of the industry itself. Contending that the packet switching industry can only be clearly perceived as the combination of the major firms that provide the service, the paper focuses on the major providers of these services: Telenet and Tymnet. The future of the industry and the entrance of such new vendors of packet switching as Boeing Computer Services and American Bell are also considered. Predicting that the major thrust in this field will be in embedding more processing features such as electronic mail, the paper argues that it is the value added features that the networks can support that must be the area of greatest potential growth. (DMC)