dictionary of slang (historical)

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http://www.campchase.com/Slang/Slang-A-F.htm
I can't remember how I found this site, but, if you have ancestors who fit the period of the US Civil War, you might find it handy;  and, if you don't, I hope you'll find it entertaining.  I fall into the latter category.
And, given that a lot of American usage is actually a reflection of English usage at the time of massive emigration, it could actually be useful with your British genealogy!