I found this caterpillar on May 27, 2014 on the ground not far from the chicken shed, brought it back to the house, looked it up in Caterpillars of Eastern North America, and identified it as a American Lady. It reportedly eats Pussytoes, so I fed it some; not surprisingly, there is a sizable stand of these near the location I found the caterpillar. The caterpillar formed its chrysalis after a relatively brief stay in captivity.
The adult emerged on June 5:
It flew away before I was able to get a photo with its wings open.