The argument over abolition usually splinters on whether the British Slave Trade Act (1807) came about as the result of moral campaigning rather than that harder interface of realpolitik; ie that there were economic motives at play. I think both of these responses are valid and need not be mutually exclusive. Just to situate ourselves a bit and maybe pick an example that certainly makes sense to me - in 1775 at the beginning of the American war of independence British crown forces promised freedom...