By Dave in Kentucky

The reason your collection only goes to the early 1940s is that by that time he had been forced off the air by the Roosevelt administration, who claimed that the First Amendment did not necessarily apply to radio, since the broadcast band was a limited resource that could be regulated. They began to require licenses for show creators as well as radio stations, and then denied Coughlin a license. He responded by pre-recording his shows and purchasing air time, infomercial style. The government then began to require that scripts for such shows be approved in advance, and threatened to pull the license of any station that did not comply. That effectively got him off the air, and they were able to shut down his magazine in much the same way, by denying him a mailing permit.