790 started off as WPFA in about 1955 according to the information I have. It had that same call sign right up until 1990, when it became WSWL, and it became WPNN is 2002.
The station had a country-western music format up until FM competition forced them out, then it was Christian music for a while, and then it was Headline News under the WSWL and WPNN calls, until the standard news/talk format we hear today.