I don’t know about the UK but in the USA slavery was abolished in the 1865, but equal rights weren’t granted until 1965. All the states were not in full compliance until the early 1970s. You could easily argue there are people still alive today directly affected by slavery.

Making slavery illegal doesn’t mean everyone suddenly starts hugging in the streets and bigotry is abolished. I’m sure these same sentiments persisted in UK but hopefully not as long as it did in the USA.