I actually went to three proms, two in my junior year in high school and one in my senior year. One of the junior proms was my own, and the other I was invited to by a friend from the neighborhood who attended a private boys school and obviously didn’t know any other girls.
Since these proms were in South Carolina, all the girls wore essentially the same dress – long sleeveless empire-waisted organza in some pastel color – with shoes dyed to match. We probably all bought our dresses, and shoes, at the same stores. My dress was pale yellow with a dark green ribbon around the waist and matching dark green shoes. Funny, I lost my prom photos years ago, but I still have the shoes.
Since the two proms my junior year were at two different schools and the only person who would be at both events was me, I didn’t see the need to get two dresses. When my senior prom came around, I decided to just modify the dress and wear it again. It was fairly simple to remove the waistband and add a lace collar and jabot. A whole different look without buying another dress. Plus, I still had the shoes.