Frederick Douglass (1818-1895) was born into slavery in America. He managed to escape and spent the rest of his life telling his story and campaigning for an end to slavery. He visited Ireland in 1845 to spread the word. I have just written an Irish Diary about his time in Ireland in the Irish Times newspaper. Read it here.
Mural of Frederick Douglass in Cork.
He also visited England, Scotland and Wales in 1845. There is a map here of all the towns where he spoke from Exeter in the south of England to Wrexham in northeast Wales and Aberdeen in Scotland.