This little butterfly is either the Frosted Elfin (Callophrys irus) or Henry's Elfin (Callophrys henrici). I am leaning towards the former species.
I photographed it in College Park, Maryland around noon today. Because of its diminutive size, when I first saw it I thought it was a moth. The picture below will give you an idea of its size relative to the leaves and the grass blades.
Adult Frosted Elfins are around in the spring for a rather short period of 2 months or so. This is the first time I have photographed this species. Hopefully, the next time the pictures will be better.