Long time lurker...first time poster! I've been gardening for 10+ years but didn't start seriously focusing on attracting butterflies until last year. I get a lot of Tiger Swallowtails, Monarchs, Skippers, Cabbage Whites, Red Admirals. I've had occasional sightings of Viceroys and Spicebush Swallowtails.
I'm thinking this is a White Admiral but not sure. I wish I got a better picture of the back-end but it was a really flighty fellow: