The history of Black Friday began in 1966, when a story appeared in an ad in The American Philatelist. The Philadelphia Police Department used the name to describe the traffic jams and crowding in the downtown stores.

In the past few years media have used it instead to refer to the beginning of the period in which retailers go from being in the red with profits to being in the black with profits- nice!

Black Friday has been the unofficial beginning of the Christmas season since the 1930s. In fact, President Franklin Delano Roosevelt moved Thanksgiving up a week during the Great Depression because retailers wanted an extra week of shopping revenue. This pleased retailers, but irritated shoppers, who had to change plans.

Black Friday has been the unofficial beginning of the Christmas season since the 1930s

Black Friday has also been known as Green Friday and is the Friday following Thanksgiving Day in the United States, traditionally the beginning of the Christmas shopping season. Hailing back to at around 1966, the day was originally popular in the East coast however since 2000 is more common in other parts of the country.
Because Thanksgiving falls on the fourth Thursday in November in the United States, Black Friday occurs between the 23rd and the 29th of November. This year it falls on Friday 23rd November. Interestingly according to Reuters, in 2007 135 million people participated in the Black Friday shopping rush.

In 2008, Black Friday sales fell 3.4% from the year before, the first time since the National Retail Federation began tracking in 1992. The 2009 holiday shopping season was only up .4%, to $437.02 billion.