When did the first talk radio show start?

I was stunned to find no almost no information on this anywhere on the internet, but I happen to know the answer.

Bert Lee invented the format in 1948 by conducting a phone interview with Harry S. Truman. The way I heard this story from Bert when he was alive is that he had started out hosting the sports report when he was younger, and transitioned into hosting music shows as early rock and roll became more popular. People could call into the radio station if they wanted to make a request, but the system was inefficient and frustrating so he asked the technicians to find a way to wire up the phones so he could take his calls himself. They eventually succeeded and the result was live talk radio which sort of pushed his career toward news and information Talk Shows.

Disclaimer- I heard that story years ago and I can't promise I remember it correctly, this is just the version I know.

Incidentally....

Does anyone know where Bert Lee went? Not literally, he died in 2004, but he seems to be almost completely absent from any place I could find on the internet. The father of talk radio, who lived a truly amazing and noteworthy life (though he wouldn't say so himself if he were alive to say anything at all), he spent his youth hanging out with the Brat Pack and he hosted radio shows from the time he was a teenager until he was 74. And he's... nowhere. No Wiki, no old radio shows I could find, not even a Word about his life in all of cyberspace.