Somerset was a slave in Jamaica who’s master brought him along to England in the 1770s, where slavery was outlawed. After getting baptized, Somerset declared himself free.

The phrase was a real crowd pleaser, for Curran. It’s no wonder later abolitionists wove it into their own writings

But instead they all probably borrowed the phrase from Irish lawyer John Philpot Curran, who deployed it often, especially during his defense of self-emancipated slave James Somerset.

Did Stowe and Douglass borrow this phrase from my favorite obscure vampire novella by an uncertain author?

That would’ve been cool

www.dbspress.com/shop-1/p/dra...

Further reading: "Hunting the Monster with Iron Teeth"
by Sandy Hobbs and David Cornwell gwern.net/doc/sociolog...

But David Castleton at The Serpents Blog suggested that the "iron teeth" aspect had much deeper roots in Glasgow: "Jenny With The Iron Teeth" circulated for generations earlier. Jenny kidnapped children for her meals. Alexander Anderson penned a poem about her in 1911.

Paul Gallagher at Dangerous Minds identified a comic book that might actually have inspired the fear-- a copy of Weird Tales from the previous year

If you thought Slenderman and deadly Grimaces were new, you're wrong. And if you think mob hysteria is a thing only adults do after sports events or political rallies, you're also wrong.

But the children returned a second night, absolutely certain that the iron-toothed monster was hungry for more innocent blood.

Authorities blamed the usual suspects-- movies and comic books
(articles from The Boston Daily Globe and The Birmingham (UK) Post)

Hundreds of kids scaled the walls of the cemetery, armed with rocks and sticks, convinced that the graveyard held a vampire who had already killed two children.

The hunt for what? A 7' tall vampire with iron teeth!