Human feet have a natural predilection for coziness. The richest among us have been snuggling our toes into pile for at least 25 centuries, according to a 1940s discovery by Russian archaeologist Sergei Rudenko. While excavating the Siberian tomb of a Scythian prince, he discovered the world’s oldest carpet, miraculously preserved through the centuries in a block of ice. 

By the 1950s, though, it wasn’t just princely toes that could afford to be warm and toasty. As the United States emerged from the Second World War, people’s minds turned from sacrifice to convenience and consumption. Gone were sugar rations and margarine—and with their new disposable incomes, Americans demanded comfort from head to literal toe. Advances in fabric technology meant that homemakers had access to ...