It's hard for me to believe that the US' freeing and integration of slaves was the first instance of this happening in history. Also, would there have been a lot of similar effects such as the current "white guilt?"
Edit: spelling
Remember that chattel slavery (plantation slavery in the U.S.) was not the same as the slavery practiced in ancient Egypt, Israel, Greece, or Rome. Additionally, many of these societies didn't conceive of race the way Americans did either (dividing people by skin color or scientifically distinguishing "races").
Slaves were considered part of the household, or familia that they served for. It was also the head of the households responsibility to ensure that their slaves were taken care of. Slaves could be freed though and were oftne incorporated into society, but were limited in certain aspects like marrying a Roman. However, freedmen and slaves were incorporated into business, like massive estate farming, and were often left to care for business by their master, or prior master.
edit: changed to Republic as most of the slaves in Rome were gained during the Punic wars and between 400-100ish BC. source: Rome by Rostovtzeff.
edit2:clarification