What civilizations used slaves?

ALMOST ALL OF THEM. It was a widely accepted practice in the Ancient world, slavery in some places are more understood than others because of the fact that the task of slaves were not properly recorded but we have reference of slavery in all of the following civilizations:

ancient Egypt, Ancient Greece, ancient Rome, Ancient China, Ancient India, Ancient Persia, Among the Aztecs and Among the Mayans among others.

Slavery was also used in the new world, however in the new world racial boundaries were used only capturing people of African (black) stock.

The West coast of Africa used slaves as did The Portuguese, The British, The Americans and The Spanish.