This "time line" of slavery is, in part taken from a talk prepared by Cameron Freeman Napier in 1993 and updated in 1997. I have not researched this but found it interesting.
She points out that there was slavery, as we know, in Biblical times. History also tells us that the Greeks, Romans, Aztecs, Africans, Arabians, Egyptians, American Indians (especially our southeastern tribes - Choctaw, Cherokee, Chickasaw, Creek and renegade Seminoles) - all practiced the despicable and inhumane practice of slavery.
Then, thanks be to God, the following actions:
1791 - Slave revolt in Haiti
1833 - Britain freed the slaves, mostly in British West Indies in Caribbean
1848 - France freed the slaves, mostly French West Indies
1861 - Tsar freed the serfs in Russia
1861-65 American Civil War (War Between the States)
1863- Lincoln's Emancipation Proclamation
1865 - 13th Amendment outlawed slavery in United States
1867 - Spain freed the slaves in Cuba and Puerto Rico
1889 - Brazil freed the slaves there.
Mrs. Napier went on to write: Slavery has continued in other forms such as: Hitler's Concentration Camps, Stalin's Gulags; African tribal warfare; Sudan, Bosnia, Deaf Mexicans in New York (I don't know anything about this).
I have read of the horrible trafficking of women and children in prostitution rings all over the world in our day and I would consider that a modern day form of slavery. It seems Satan continues to be alive and well in exploiting the week and helpless as He always has.