Tights

Tights first went on the mass market in 1968. Though now regarded as the antithesis of erotica, it was tights that sent hemlines higher than ever before in history - in London that year, dry cleaners charged for skirts by the inch. The knock-on effect was the real liberation, though: short skirts dictated low-heeled shoes. Women (then called girls) were able to walk in comfort. Also march, run, and climb on barricades if required.