What did the term "Black Friday" originally mean?

I thought it meant sales were so good the day after Thanksgiving, all stores would make huge profits and be “in the black”, not “in the “red. I am 73 years old and never heard this traffic explanation.

Black Friday has nothing to do with traffic. It has everything to do with stores’ profits moving into the black, I.e. making a profit. Whoever dreamed up this explanation has no clue.