Who made the first public video call?

The Covid-19 pandemic has caused a massive boost in the use of video conferencing technology.

This is because the social distancing rules mean most people are advised to work from home. Video conferencing helps with this tremendously, and like every technology, it has a history.

The idea itself first emerged in the 1870's, and was in the realm of science fiction. There was even a recognisable term for it: videotelephony. Various research projects made some progress alongside the invention of the television, but most involved just two transmitters and receivers, so weren't switchable in the way the term "public" meant. The first actual public one which could be described this way, because each party could connect to any of several different parties on the same network, was actually created in 1936 and known as the Gegensehn-Fernsprechanlagen system, It connected the cities of Berlin and Leipzig, and the governing party of the day was indeed the Nazi party.

Dr. George Oskar Schubert

Dr. George Oskar Schubert led the research and development department at Fernsh AG in 1936. There had been various designs for video telephone systems up until then, but these always just connected two points directly, and often only had video one way. The system he designed allowed callers to choose from several destinations, but it's complexity meant that it could only be installed in post offices, but at least this meant it was available to the public.

The system used in 1936 used dedicated co-ax cables, and manual operators switched them on demand to connect to the required destinations. It wasn't until the 1950's that attempts to use the regular telephone networks were made, and with the slow scan refresh rates these were of dubious usable quality.

There is a class of Mandela Effect which is known as tech before its time.  This is where some technology has been shows to exist which appears "all of a sudden", and its origin would be expected to have been common knowledge. Examples are the first car to hitt 100kph being electric, and the world's first telecoms hack. This example of the public video conferencing system is of this kind, and made even more surprising by the fact it was created by the Nazis. Who knows how it could have affected history, or indeed changed the war, it it had become more advanced at the time.