The story
The idea (and hence presumably the name) developed in the United States, and then went global. (Reference: Trevor Sykes, The Bold Riders, second edition, 1996, →ISBN, page 8.)
Etymology from Wiktionary, CC BY-SA 4.0.
negative pledge
Today it means: A type of loan or loan condition in which the borrower agrees with the lender not to allow any other lender or creditor to rank ahead for payment in the event of a liquidation. Such a loan is unsecured (ie. not backed by a charge over specific assets). Full definition →