Like many classic pieces of outerwear, the fishtail parka has roots within military. The standard issue cold weather parka in the 1940s was the N3-B or snorkel parka, but the cold and wet conditions of Korea meant that a warmer coat for American troops was needed during the Korean War...
C.I.V History | Fishtail Parka
Article by COMMON ILKE VINTAGE
Back to the drawing board
The Army designers went back to the drawing board and developed the M-1951 Cold Weather Parka as a result. The key concern for the US military during the Korean War was to keep the soldiers warm and agile without wearing a thick and restricting piece of outwear. The fishtail parka accomplished these needs with a three-quarter length, so it could keep someone’s entire body warm without hindering their movement.
The famous fishtail
The jacket was constructed out of waterproof nylon and cotton, so Korean snow and rain would roll off the jacket. But the true innovation came from the split in the back of the jacket with a drawstring on each hem. The wearer could tie each half of the split around each leg, this trapped more heat and kept the wind out. Many GIs thought the split looked like the tail of a fish, and thus the fishtail name was born.