Most prom dresses live in relative obscurity. Oh, sure, they have that one night of glory, swishing and showing off on the dance floor. But then back to the closet they go. The exception is dress No.

When I picked out my first prom dress 28 years ago, I’m not sure I had much of a vision in mind other than finding a dress that was long enough — which can be a challenge for a lanky, 6-foot-tall ...