AT&T Corp. is a major American telecommunications company that provides a wide range of services, including mobile and fixed-line telephone services, broadband internet, and digital television. Founded in 1885, it has grown to become one of the largest telecommunications providers in the world, serving millions of customers across the United States. The company operates under various segments, including AT&T Mobility, which focuses on wireless services, and AT&T Business, which caters to enterprise customers. In addition to telecommunications, AT&T Corp. has expanded into media and entertainment through its ownership of WarnerMedia, enhancing its offerings in content and streaming services.