This is from memory, so please don't sue if I get details wrong

Back in either the late '70s or early '80s, Eastern Airlines set up a deal with a major freight company to use EA's passenger planes for overnight freight runs. As part of the plan, Eastern sold seats to passengers, who could fly from one coast to the other by way of a stop in the single hub, which was in Houston (I'm not sure if EA used Intercontinental or Hobby).

The service was called something like "Moon Light Flyer" or "Moonlight Special" or something similar, and IIRC the one-way trasnscon fare was ~$100.