interesting threat, i am from germany originally but was always attracted to the american south of that time. the book you were looking for may have been this one? :
Code Words used in "slave songs" and their definitions:
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Baggage - escaping slave...
allison :
i am from germany [currently living in the U.S.] and can tell you that "gutz" is definitely not a "proper" german word - the only thing it reminds me of is some local dialects where "gutz" is used for the proper german word "gutes" = something that is good.
but that has...