Hickock, according to Wikipedia

On July 21, 1865, in the town square of Springfield, Hickok met and killed Davis Tutt in a "quick draw duel" –the first of its kind. Fiction later popularized Hickok's "quick draw gunfight" as typical, but Hickok's is the first one on record to fit the portrayal. During the duel, rather than the face-to-face fast-draw as is commonly shown in movies, the two men faced each other sideways in the historic dueling stance, drawing and aiming their weapons before firing.

^{I cannot verify the accuracy of this, but it is interesting.}