Moved from ID Request.

since this more recent photo still has the entire tail on the right hind wing, and different nicks in the wings. This is a male "Dod's Swallowtail" (listed as P. machaon ssp. dodi here on BugGuide - but - many, including me, would call it P. bairdii ssp. dodi). I've never been clear on where to draw the line between ssp. bairdii and dodi, and those from Nebraska have been called both. However, lately, all of the Great Plains populations are usually referred to dodi. The naming is a bit confusing, but yes, by the classification followed here it's an "Old World Swallowtail" by association.

Another point of interest. I'm not sure about the first photo, and not certain about this one either, but it looks like both are perhaps sitting on the larval host plant - Artemesia dracunculoides (lumped with European A. dracunculus by many). You might find caterpillars soon.