Frederick Douglass

Douglass spent time in Scotland and was appointed "Scotland's Antislavery agent."
He made anti-slavery speeches and wrote letters back to the USA. He considered the city of Edinburgh to be elegant, grand and very welcoming. Maps of the places in the city that were important to his stay are held by the National Library of Scotland.
A plaque and a mural on Gilmore Place in Edinburgh mark his stay there in 1846.

https://en.m.wikipedia.org/wiki/Frederick_Douglass