Oh the irony. Suggestion: if you're wanna be a playa, you might consider coming prepared. The arguments the British make about American independence and slavery are exactly the same associations made with respect to the Confederacy. But, because I'm a nice guy, I usually provide some informational links to help potential allies up their rhetorical game so to say.
1772 - after decades of abolitionist agitation within the church/society of England, the High court decides that slavery has no common law support. Ergo, the slaves are freed. https://en.wikipedia.org/wiki/Somerset_v_Stewart
1776 - US declares independence. All 13 states still preserve slavery as a core feature within their respective charters. PA is the first 'state' in 1780 to begin introducing abolitionist legislation https://en.wikipedia.org/wiki/Slave_states_and_free_states
You might know that the earliest divide in the US - in fact, the one that eventually manifested in the first Civil war - wasn't really about slavery per se, but the political legacy each region experienced from the original founding of the two key colonies: Plymouth (New England) and London (Virginia). As is quite evident, the reason certain northern states were the earliest to abolish slavery were they where the ones in closest alliance/influence from England and English intellectual thought. Virginia was associated with the French and a more rigid, stratified society.
Anyway, this is the thinking behind the arguments made by the Guardian, et al. They make a very good point: how come Washington & Jefferson, the two richest men in N America and both slave holders are heroes gaining independence, while those who led the South under exact same rationale, are somehow just historical footnotes?
I was kicked off The Guardian years ago.