Despite the bell-bottom and platform-shoe revival of the early 2000s, it is unlikely that anyone will remember the 1970s for the quality of its innovations in fashion. In fact, many of the favorite fashions of the 1970s are now remembered with humor. Hot pants, polyester leisure suits, and mood rings—what were they thinking?

The fashion excesses of the 1970s can be partially blamed on the widespread use of polyester. Clothing designers latched onto this fabric and offered Americans brightly colored knit shirts with a silky sheen, "wild" hot pants and miniskirts in an array of chemically enhanced colors, and comfortable leisure suits for wearing to the disco. The sheer novelty of the styles and colors drew people to the clothes, but it was not until the late 1970s that many realized just how ugly those clothes had become.

Novelty also explained the popularity...