England, and later Britain, profited from the Atlantic triangular slave trade for 200 odd years from the early 17th century until abolition in 1807 (slavery was not fully abolished within the British Empire until 1833 - some exceptions remained until 1843).
This trade is recognized for the evil it was.That's the point. England / Britain's role is made very clear through education, at public memorials, in the media and at locations where the trade was centred such as London, Liverpool and Bristol. There is a lot of interest across the country in understanding what happened, the history and Britain's involvement.
The Confederate flag issue suggests this is not the case in the Southern States.