In the early days of telephony, through roughly the 1960s, companies used manual telephone switchboards and switchboard operators connected each call by inserting a pair of phone plugs into the appropriate jacks. Each pair of plugs was part of a cord circuit with a switch associated that let the operator participate in the call. Each jack had a light above it that lit when the telephone receiver was lifted (the earliest systems required a generator on the phone to be cranked by hand). Lines from the central office were usually arranged along the bottom row. Before the advent of operator distance dialing and customer Direct Dial (DDD) calling, switchboard operators would work with their counterparts in the distant central office to complete long distance calls. With the development of computerized telephone dialing systems, many telephone calls which previously required a live operator can be placed automatically by the calling party without additional human intervention.
Before the advent of automatic exchanges, an operator's assistance was required for anything other than calling telephones across a shared party line. Callers spoke to an operator at a Central Office who then connected a cord to the proper circuit in order to complete the call. Being in complete control of the call, the operator was in a position to listen to private conversations. Automatic, or Dial systems were developed in the 1920s to reduce labor costs as usage increased, and to ensure privacy to the customer. As phone systems became more sophisticated, less direct intervention by the telephone operator was necessary to complete calls.
As well as those employed by the public networks, operators were required at private branch exchanges to answer incoming telephone calls and connect them to the correct extension. Today, most large organizations have direct-dial extensions. Smaller workplaces may have an automated system which allows callers to enter the extension of the called party, or a receptionist who answers calls and performs operator duties. Depending on the employment setting, the roles and level of responsibilities of a PBX operator can vary greatly, from performing wake-up calls in a hotel to coordinating emergency responses, dispatching, and overhead paging in hospitals. Operators employed in healthcare settings have other duties, such as data entry, greeting patients and visitors, taking messages, triaging, or acting as an after hours answering service. Experienced, well trained operators generally command a higher salary.
A note: in the United States of America, any switchboard operator employed by an independently owned public telephone company which has not more than seven hundred and fifty stations was excluded from the Equal Pay Act of 1963.
In January 1878 George Willard Croy became the world's first telephone operator when he started working for the Boston Telephone Despatch company.
Emma Nutt became the world's first female telephone operator on 1 September 1878 when she started working for the Boston Telephone Dispatch company, because the attitude and behaviour of the teenage boys previously employed as operators was unacceptable. Emma was hired by Alexander Graham Bell, and reportedly, could remember every number in the telephone directory of the New England Telephone Company.