In a Nutshell, the UK in a Civil Action, paid money with interest over time, and their former Colonies, in the USA paid blood, through a violent Civil War, to alleviate and eliminate the same problem of a
UK originating, horrid institution.
https://taxjustice.net/2020/06/09/slavery-compensation-uk-questions/
https://en.wikipedia.org/wiki/Slave_Compensation_Act_1837
https://www.usatoday.com/story/news/factcheck/2020/06/30/fact-check-u-k-paid-off-debts-slave-owning-families-2015/3283908001/
https://www.history.com/this-day-in-history/october-16/john-browns-raid-on-harpers-ferry