I heard once from a professor at Uni that main reason for this is the lack of broadcasting equipment of sufficient power to cover whole USA area (and thus provide a broadcast that could be received by millions simultaneously) at a time when radio and TV were becoming popular. Is this true? Also from this I conclude that is why so many smaller broadcasting companies were established throughout US rather in commercial manner than to broadcast state-funded content without additional charge. Was government ever involved or interested in running a public radio or TV station? I know that currently some public spendings are made to PBS but thats still not a public station in my undestanding.

I know this is broad and involved physics, history and whatnot but this subreddit seems to be the best place to ask such questions.

Sorry for my english, im not a native speaker.