ELI5 Black Friday - why is it called Black Friday?

Why is it called Black Friday? Why is thanksgiving itself always on a Thursday? Was Macy’s the first American department store to sponsor a parade in celebration of Thanksgiving? How did American football become such a big part of the thanksgiving tradition? Is it true that the day after Thanksgiving is the busiest day for plumbers? ... we explain like I'm five Thank you to the r/explainlikeimfive community and in particular the following users whose questions and comments formed the basis of this discussion. To the ELI5 community that has supported us so far, thanks for all your feedback and comments. Join us on Twitter: https://www.twitter.com/eli5ThePodcast/ or send us an e-mail: ELI5ThePodcast@gmail.com