In the early days of telephony, companies used manual telephone switchboards, and switchboard operators connected calls by inserting a pair of phone plugs into the appropriate jacks. They were gradual
Seattle telephone operators in a private branch exchange in 1952
New York telephone exchange in the 1880s, with both men and women as operators
Paris telephone exchange, 1900
Telephone operators in Stockholm, Sweden 1902–1903
Hello Girls, formally the Signal Corps Female Telephone Operators Unit, were American female switchboard operators in World War I. During the war, these switchboard operators were sworn into the U.S.
Switchboard operator
…operators were in the "Women of the Signal Corps Female Telephone Operators Unit" of the American Expeditionary Forces in 1917–1919, also known as the Hello Girls. They were bilingual female switchboard operators sent to France during World War I. These operators were not formally recognized for their military…
Hello Girls operating switchboards at general headquarters in Chaumont, France (November 5, 1918)
American telephone girls arriving for "hello" duty in France (March 1918}
Chief Operator Grace Banker receiving the Distinguished Service Medal
Poster for the United War Work Campaign (November 11–18, 1918)