Though Black Friday officially opens the Christmas shopping season bringing massive traffic jams and over-crowded sidewalks, the term “Black Friday” wasn't coined to describe the day after Thanksgiving until the mid-1960s and even back then, it wasn't a popular term nationally until around the last twenty years.
The earliest documented relation to this was in Gregorian calendar month 1966 once written by bonny Taylor-Black of the yank idiom Society remarks that Black Fri is that the name Metropolis Police Department has given to the Friday following Thanksgiving Day.
Black Friday is not the biggest shopping day of the year yet nearly 135 million people go out to shop on Black Friday every year reportedly hundreds of billions.