A brief history of the “clenched fist” image.

“A persistent symbol of resistance and unity, the clenched fist (or raised fist) is part of the broader genre of ‘hand’ symbols that include the peace ‘V,’ the forward-thrust-fist, and the clasped hands. The clenched fist usually appears in full frontal display showing all fingers and is occasionally integrated with other images such as a peace symbol or tool.... Fists, in some form, were used in numerous political graphic genres, including the French and Soviet revolutions and the United States Communist Party. However, these all followed an iconographic convention. The fist was always part of something — holding a tool or other symbol, part of an arm or human figure, or shown in action (smashing, etc.). But graphic artists from the New Left changed that in 1968, with an entirely new treatment. This ‘new’ fist stood out with its stark simplicity, coupled with an popularly understood meaning of rebellion and militance.” (via)