This one has an angled bar that starts on the rim and goes through the E in STATES and extends all the way down to the base of the right-most pillar. There is also a smaller and shorter bar that runs parallel to the primary one just east of the memorial. Also, there is a similar bar the starts at Lincoln's neck and extends at the same angle to the top left of the 6th pillar. Any info?
dave: Looks like a clash mark, but unusual since it would not line up with the obverse. perhaps overpolishing of the die?
Mike, I have similar long lines on other Cents! Could this be a case where some foreign material (metal shavings, shards) fell onto the Die and damaged the Reverse Die when striking a previously minted Cent? If so, then there may be another 1978-P Cent out there with pieces of metal struck into the Reverse! Frank
Most of the raised lines I've seen have been on copper-plated zinc cents. On the latter they appear to arise from a variety of causes. Some are linear bubbles (not applicable to solid-alloy cents). Some appear to be die scrapes from a feeder finger. Other's I'm not sure about. The thing about die damage is that it's very seldom that you can pinpoint a cause.