Earlier quoted context omitted.
History books about things that happened rather than, say, squinting hard to rationalise unhappy truths? Britain didn't have slavery†. The 1833 act abolishes slavery in the Colonies, not in Britain itself. The existence of slavery in the colonies is why there were slaves in America to seek freedom by fighting for the British there. So like I said, the British freed those on their side, while the colonists unsurprisin…
So Britain didn't exist until 1833? It wouldn't have been in the US if Britain didn't bring it.
The Colonies weren't Britain. Their people weren't (on the whole) British citizens, if you knew a bit more history that year might stand out more. 1833 is just after Great Reform, the country has become more small-D democratic, expanding the franchise (the right to vote) to more men and eliminating "Rotten boroughs" which were often in practice controlled by rich people, including slaveowner colonists abroad.