Frankly, I doubt that there's a nation on this earth which hasn't been involved at some point in history or other. If we want to show an apology for the foul trade of slavery, then by all means do so - by contributing to an international effective force to wipe it out globally. There are more slaves now than at any other time in history. Instead of giving money to people who haven't suffered, use it to free people who are suffering now.
Plus - I'm from the North East. My ancestors weren't slaves - they were worse, because they had no value to their employers. If my great-grandfather was too ill to get himself down a mine for a 12 hour shift 2 miles underground crawling along an 18" seam and hacking out coal and shoving it behind him for a 10 year-old boy to load into a rail cart (a shift that didn't start until he was at the coal face, and that could easily take an hour of travel ), then he didn't get paid and he and his whole family starved. Those pits were often half-filled with water, or oozed toxic gasses.
If pitmen and boys (and women and girls for that matter) died in an explosion, were crushed in roof-falls, or were suffocated or drowned, their families got nothing - compensation was unheard of - and often lost their homes if the wage-earner was in a "tied" cottage. This happened everywhere there were mines, from the coal-mines of the North to the tin and copper mines of the South.
And every other industry was the same. Men, women and children exploited, used and cast aside to fill the pockets of the bosses. A slave-owner had an investment in his "property" and would at least feed and house them (often appallingly, I admit), but these "wage slaves" got nothing at all if they couldn't work for any reason. I'm not trying to minimise the slave trade - it was appalling. No human being should be owned. But you cannot take people out of history.
There are many forms of slavery. None of them are acceptable. Historically all of us have suffered in one way or another. How far back do we go? Can I claim compensation for the Viking Invasions along the NE coastline? Or for the very likely fact that (at least) one of my ancestresses was raped - my blood group indicates that I have Mongol blood coursing through my veins?
This "reparations" stuff - and apologies from "people who have done nothing to people who have suffered nothing" is nonsense.
Stamp out modern slavery and let the past be the past - we must never forget it, and never repeat it. And not to repeat it is the greatest respect and acknowledgement that we can offer,