Frank Mullen the founder of KDKA. somehow Louise Margaret Benjamin skips that link in her book The NBC Advisory Council and Radio Programming. She only connects it back to an experimental radio pilot called the Dinner Bell Hour on NBC. It's also worth noting that the Bibliography on Educational Broadcasting by Isabella Mitchell Cooper also credits Frank Mullen on KDKA via a citation to a 1935 article printed by NBC, "Radio For the Farm Folks, How the Farm Hour Started.That's a solid source.
The program would continue to run for three decades. It was sponsored by the U.S. Department of Agriculture and American Farm Bureau, 4-H Club, Farmers Union, Montgomery Ward, The Future Farmers of America (FFA) and the National Grange. It's not surprising to see them on a list together, but the program was intended for rural listeners in farming communities. For context try to remember that Rural Free Delivery was only adopted in 1902, and rural electrification only began in 1932. It was a civic-minded era, and the Secretary of Agriculture liked to broadcast the occasional speech from time to time as well.
The program was a true variety show. It had an orchestra, musical guests, comedy skits and a re-occurring park ranger character played by Don Ameche. But it's core was weather and agricultural news which is how the secretary of the Dept of Agriculture coudl act as it's producer. In June of 1945 NBC Blue became ABC and the National Farm and Home Hour moved to NBC as a 30 minute program. It was still being carried on over 100 stations. It remained there until 1958 with Allis-Chalmers as it's primary sponsor. It died with a whimper spending it's last 3 years as a segment on NBC's weekend anthology Monitor. The program was cancelled in 1958.
It's most famous host was Everett Mitchell. He was on the program from 1932 onward. His trademark line was "It's a beautiful day in Chicago!" Mitchell was a former insurance claim adjustor who broke into radio singing part-time at radio station WENR-AM. A belligerent manager made him choose between radio and insurance. He picked the latter. Nemorino writes that over the course of his career he also spent time on WQJ, WEBH, and WHT.
It's hard to find citations but WQJ was a short-lived dayshare with WMAQ owned by the Calumet Baking Powder Company and a local Chicago venue, the Rainbo Gardens Ballroom. WMAQ bought them out in 1927. WEBH was another Chicago station, this one owned by the Edgewater Beach Hotel. WEBH is even more fleeting, a dayshare with WDAP. They signed on in 1923 and were deleted in 1928. (That license became WGN.) WHT was owned by the Radiophone Broadcasting Corporation, in Deerfield, IL a suburb of Chicago. They operated just in 1927 and 1926 as far as I can tell. But it shows that he had at most a few years experience before landing that job as host of the Farm Hour. years after the program ended, in 1967 Mitchell received the Great Service to America Award and retired that year. He died in 1990. Frank Mullen died in 1977 and farm radio continues to wither to this day.