The British paid huge amounts of public money to other countries to set slaves free. Britain is the country went into armed conflict to force the Atlantic slave trade to cease.
Yes, we were a part of it before then, but we are the only nation which saw the evil of the norm and reversed it's position, putting money and military into securing the freedom of those living the trauma. Not entitled parasites hundreds of years after the fact.
The correct response to people wanting reparations today today is "Bugger off! You're 200 years too late. Go bother the people that we bought your ancestors freedom from. "