It might be hard to believe that for much of human history, slavery was a norm, so much so that the very idea of having it abolished seemed like a maverick idea dreamt up by those without a grip on reality.

It was just over 200 years ago – in 1804 when Haiti (then Saint-Domingue) formally declared independence from France in 1804 and became the first sovereign nation in the western hemisphere to unconditionally abolish slavery in the modern era...