[Jolly Amaranto]

According to the "History Guy" the first use of the term "Black Friday" occurred in an industrial journal published in 1951 and was referring to the trend of a large number of employees calling in sick that day in order to go shopping. It was not until the 1980 when retailers started spreading the friendlier story of the red ink to black ink.
He mentions it in the fists part of this video.