It was kind of a mixed bag. Part of the way this worked was that USPS was actually paying for a lot of the rail services to deliver mail (which is also what th

It was kind of a mixed bag. Part of the way this worked was that USPS was actually paying for a lot of the rail services to deliver mail (which is also what the government wanted more so than passenger rail service.) The moment USPS pulled contracts in favor of long-distance airmail the whole model went belly-up.