The Brits like to crow about having abolished slavery in 1833 but the 1833 law only applied to the British isles, the Caribbean colonies and South Africa but not the remainder of Africa or the Asian colonies.
British East Africa (roughly the same area as is modern Kenya) had slavery until 1904, British Malaya (the Malay peninsula and modern Singapore) until 1915, and the British government in India allowed indentured servitude among the natives until 1917. British Burma until 1926, and British Hong Kong was still practicing a form of slavery limited to young women used as domestic servants until the 1930s.
The (white) Australians practiced de facto slavery of the Aborigines until the middle of the 20th Century. It wasn’t chattel slavery in that they weren’t openly sold in markets but they were confined and held against their will, sometimes in chains, and always restrained by financial means. And the practice was only ended because Aussie labor unions finally gained the political clout to have it ended so that the Aboriginal labor wouldn’t be unfair competition to them.
The Brits deserve credit for 1833.
But we also deserve credit. For 1770, 1772, 1775, and any other year these laws were passed. And any veto that prevented these laws from becoming finalized, well the Brits deserve credit (I mean scornful) for that too.