These butterflies rarely open their wings as the individual here from September 2017 unless they are basking in the sun. Even then, the wings are only partially open. Species like Pearl Crescents are superficially similar in that they are orange and fly in similar habitats as these guys, but are larger and often give nice dorsal views to help pick them out. You will also likely see grass skippers in similar habitats and they can also flash in orange, but have a different flight style and body shape. Eastern tailed-Blues and Gray Hairstreaks are similar in size but have only a little bit of orange on the wings.