One of the first people to build a telephone exchange was Hungarian Tivadar Puskas (above) in 1877 while he was working for Thomas Edison. George W. Coy designed and built the first commercial telephone exchange which opened in New Haven, Connecticut. He’s been called the first full-time telephone operator. The switchboard was built from "carriage bolts, handles from teapot lids and bustle wire" and could handle two simultaneous conversations .
The first telephone switchboard built by George W. Coy
The first was in Boston, 1877 (experimental).