Subject: How can an FM or AM broadcast be heard simultaneously nationwide?

Shows like NPR, Rush Limbaugh, etc. are heard in all parts of
the country at the same time.  I know that only shortwave radio has
the power to travel through the air over such long distances.  Does
that mean that the stations that carry such shows in different cities are
all connected by dedicated wires or some such mechanism?  If so, was
this also the case in the early days of radio, e.g. Roosevelt's andquot;Fireside
Chatsandquot; etc.?

Re: How can an FM or AM broadcast be heard simultaneously nationwide?