Philadelphia police used Black Friday to describe chaos and congestion.

Downtown streets were clogged with hordes of shoppers headed to the big department stores.

Retailers hated the terms but then tried to reinvent it.

It was the day their profits went from red to black.

So they said, Black Friday really started catching on in the eighties and nineties, pushed by the growth of big box stores.

Today, it's all about bargains, and Black Friday is dark.

Roots are for the history books.