When did switchboard operators become a common job?

Switchboard operators became a common job in the late 19th century with the rise of telephone technology. As telephones became more widespread, the demand for switchboard operators increased. By the 1920s, there were over 200,000 switchboard operators in the United States alone. However, with the introduction of automated switchboards and computer technology, the need for manual switchboard operators declined, leading to their eventual phase-out in the late 20th century.