Greater black population in Britain pre-WWII

How could Britain have a greater population of black ppl prior to WWII ? Historically, Britain, including London, has had black ppl living there since Roman times, and there were racial tensions post-WWI (like the US Red Summer), when unemployed black seamen clashed with whites in such places as Liverpool in summer 1919 over jobs and local women, although it was only after WWII that large nos. of West Indians and ppl from the Indian subcontinent started emigrating to the UK and establishing their own distinct ethnic communities. What POD/s would be required for blacks to form as significant a portion of Britain's pop as they do now, at an earlier stage of hist ? What about something like larger nos. of former freed slaves after the ARW, repatriated from the South and NY to British ports, deciding to stay in England instead of OTL travelling to the West Indies or Sierra Leone ? Would such a higher percentage of blacks in the British pop have necessarily resulted in the 'rivers of blood' foreshadowed by Enoch Powell in the 60s, or would racism in Britain have not been as virulent as in the US ? How would Britain with a greater black pop have reacted to and influenced a US which continued to practice Jim Crow segregation ?

Well the black population of Britain was big during the 18th century its just during the 19th they interbred with the whites and died down a bit.
I suppose a way to get more of them is to have people be more racist and stick to their own kind.

---How would Britain with a greater black pop have reacted to and influenced a US which continued to practice Jim Crow segregation ?----


OTL the accepting attitudes of many white Britons towards African-American soliders was a plus in inspiring the soldiers to push for change once they got back to the US.Assuming that the greater black population was older and more intergrated than the one OTL this could help -perhaps Britian would refuse to allow segregated facilites.

I fear that a greater black population in the 30s would have meant stronger racism in Britain. As noted the relatively tiny black populations suffered awful attocities in the aftermath of WW1

I fear that the high unemploymernt would have made blacks a target.

I guess if you could have had relatively succesful integration- which I as a white Brit think we more or less have now- then there would be a VERY sharp problem with America's Jim Crow. However that might have needed ASBs.

Also even if Britain was more agreed on an anti racist stance I fear that we would have had to accept American "Customs" simply because we REALLY NEEDED American servicmen to fight the worst evil in the World.