France soon adhered to the new treaty; but the States of South America, and the Spanish and Portuguese colonies, did not join in the Act of Abolition.

The exportation of blacks then continued to their profit, notwithstanding the right of search generally recognized, which was limited to the verification of the flag of suspicious vessels.
Meanwhile, the new Law of Abolition had not a retroactive effect.

No more new slaves were made, but the old ones had not yet recovered their liberty.
It was under those circumstances that England set an example.

In May, 1833, a general declaration emancipated all the blacks in the colonies of Great Britain, and in August, 1838, six hundred and seventy thousand slaves were declared free.
Ten years later, in 1848, the Republic emancipated the slaves of the French colonies, say about two hundred and sixty thousand blacks.

In 1861, the war which broke out between the Federals and Confederates, of the United States, finishing the work of emancipation, extended it to all North America.
The three great powers had then accomplished this work of humanity.