Why is the day after Thanksgiving called "Black Friday"?

As we slowly approach Turkey Day and the associated festivities of food, football and family, one must not forget the fourth tradition that has slowly grown in popularity over the last 10 to 15 years - BLACK FRIDAY!

But why is it called "Black Friday"?  Certainly, there is nothing dark or foreboding about this day.  The popular theory that has been bandied about recently is that the term comes from the notion that businesses finally go from being in the red (or in debt) to the black on this day because of the increased number of sales and purchases from bargain hunters!  However, that theory seems silly, because if a business were to base its level of yearly success on only one day of shopping, clearly that business owner needs to consider a new line of work!

So when was the first incarnation of this term?

It appears that the first reference comes from the 1950s from factory owners who noted that their workers did not show up to work the day after Thanksgiving.

It was not until the early 1960's when we see the first instance of its use to describe the post-Thanksgiving holiday shopping rush.  As a result of the traffic from the mayhem of shoppers to Philadelphia, police coined the term as a description of the harrowing scene on that day.

So, in fact, although today's shoppers see "Black Friday" as a wonderful opportunity to keep a little extra cash in the wallet while getting a nice gift or present, the term was derived from a not-so-pleasant experience that began nearly 50+ years ago!  (Although some would argue that "Black Friday" still carries that negative connotation today!)

Source:
1.  http://www.visualthesaurus.com/cm/wordroutes/the-origins-of-black-friday/