The term "Black Friday" originated in Philadelphia. In the early 1960s, Philadelphia police griped about the congested streets, clogged with motorists and pedestrians heading to the Army-Navy football game and looking for deals post-Thanksgiving, calling it “Black Friday.”
As retailers began to realize they could draw big crowds by discounting prices, Black Friday became the day to shop, even better than those last-minute Christmas sales. Some retailers put their items up for sale on the morning of Thanksgiving, or email online specials to consumers days or weeks before the actual event.