The Full Story
By 1850, Brazil was the last major destination for enslaved Africans. Despite treaties and promises, Brazilian merchants continued importing tens of thousands of people each year. Britain had been patient. Britain had been diplomatic. Brazil had ignored them.
So Britain stopped asking.
The Aberdeen Act of 1845 gave the Royal Navy authority to treat Brazilian slave ships as pirates, seizable on the high seas. But when that wasn't enough, British warships sailed directly into Brazilian harbours. They burned slave ships at anchor. They chased slavers up rivers. They operated in Brazilian territorial waters as if Brazil's sovereignty didn't exist.
Brazil was outraged. The international community was shocked. But within months, Brazil passed its own anti-slave-trade law, the Eusebio de Queiros Law of 1850. The Atlantic slave trade to Brazil, which had transported more enslaved Africans than any other route, collapsed almost overnight.
Britain had committed what would today be called acts of war. The result was the end of the largest slave trade in the Americas.
Why This Matters
This shows how far Britain was willing to go to end the slave trade. When diplomacy failed, Britain used force. Even against a sovereign nation. Even at risk of war. The end of Brazilian slave imports was a direct result of British naval intervention.