"Tar paper", commonly known as "felt" in the roofing business, comes in 36' tall rolls. I would submit that any felt I have seen in my lifetime would be a very temporary performer as a rooftop weatherproofing. It is typically used UNDER asphaltic shingles or rolled roofing to stop the wood underbuild from drawing the tar out of the actual roofing. Are you referring to rolled asphalt roofing ? If so, this product is sold in the same 36" tall rolls.
I have seen old houses sided with this stuff too, but am unfamiliar with how the RR's might have used it.