In the otherwise excellent ‘The white curse’ (View from the South, NI 370) Eduardo Galeano fails to distinguish clearly between slavery and the slave trade. It was the slave trade that Britain abolished in 1807. Slavery itself continued in British possessions, principally in the Caribbean, until 1832.
The British record on slavery is somewhat better than he concedes. It was abolished in Britain as early as 1744, by the well-known Court decision in the case of the runaway slave James Somerset, which decreed that as soon as a slave set foot in England, they were free.