"The Problem of Slavery in the Age of Emancipation"

[Eva Elisabeth]

As for Brazil, an interesting addition from Wiki and a NY Times article:

"Slavery was not legally ended nationwide until 1888 by the Lei Áurea ('Golden Act'), a legal act promulgated on May 13 by Isabel, Princess Imperial of Brazil. In fact, it was an institution in decline by this time (since the 1880s the country began to attract European immigrant labor instead). Brazil was the last nation in the Western world to abolish slavery, and by abolition had imported an estimated total of four million slaves from Africa. This was 40% of all slaves shipped to the Americas."

"Soon after Princess Isabel, officially ended slavery, disgruntled landowners united with the military to finish with monarchy altogether, forcing the royal family back to Portugal and founding Brazil's first republican government on November 15, 1889. A long series of easily forgettable presidents, backed by strong coffee and rubber economies, brought about some industrial and urban development during what's known as the Old Republic."

(My additional comment: ) Also serfdom in many European countries was the same as slavery. There were many serf/peasant revolts, and many serfs have been freed in the course of the Napoleonic Wars. And most of the many wars in the world and its history were led for ethically lower motives than democracy and emancipation.
Scroll down for a list of of states where serfdom existed and the respective dates of emancipation:
https://en.m.wikipedia.org/wiki/Serfdom