AT&T Corp., originally the American Telephone and Telegraph Company, is the subsidiary of AT&T that provides voice, video, data, and Internet telecommunications and professional services to businesses, consumers, and government agencies. During its long history, AT&T was at times the world's largest telephone company, the world's largest cable television operator, and a regulated monopoly. At its peak in the 1950s and 1960s, it employed one million people and its revenue was roughly $3 billion annually.