Happy National Flip-Flop Day! Believe it or not, flip-flops have been worn by many cultures worldwide, originating in Ancient Egypt as early as 1500 BC! These sandals were made of papyrus and palm leaves. In Africa, the Maasai people made their sandals out of rawhide, in India they were made of wood, and in China and Japan, rice straw was used. The ancient Greeks and Romans also wore versions of flip-flops, but the Romans wore the strap between the 2nd and 3rd toes, while the Mesopotamians wore it between their 3rd and 4th toes! Flip-Flops became popular here in the U.S. when soldiers returning from World War II brought Japanese zori sandals home. They quickly became popular and in the 1960s were firmly associated with the beach lifestyle of California. Today, around 3 billion new pairs of flip-flops are produced globally each year. Learn more here.