the ventral surface of the forewing had no black around the apex and the legs would be white.

but appears uncommon http://butterfliesofamerica.com/imagehtmls/Hesperiinae/208_Ancyloxypha_numitor_Newport_Cooke_Co_TN_USA_20-VI-78_C2_3_i.htm

Also I note faint antennal stripes when I expand the image.

Generally, that is true about the forewing. This butterfly has the very long FW shape, the very long and thin abdomen, more or less white legs, and the white rays on the HW ventrally. There is no other skipper in Delaware with these body/wing proportions.
I don't know how to insert another BG photo here, but look at 105432 (wrong number originally). I know, I called it back then. But that old butterfly approaches the color of this one the most. It does have the long FW, long abdomen, striped antennae, and white legs that we would expect. Of course, you can't see the white rays on the HW because that is somewhat aberrant. I would have to say that the current individual is also somewhat aberrant, but this sort of thing happens occasionally in various butterfly species..

Thank you for the explanation! I can see now that it's a (slightly unusual) Least Skipper. Should have trusted my first instinct, I guess.