Slavery was part of Roman culture, but if you had to pick, it may have been better to be a slave in ancient Rome than in pre-Civil War America. Sometimes.
Slavery was not a life sentence in Rome. Slaves could earn their freedom or be granted manumission (their release from slavery) by their masters, and, once freed, became full Roman citizens.
There is evidence of Romans buying slaves in another land, taking them home, and freeing them. One gravemarker for a freed slave tells the story of this. Her husband bought her, took her home, freed her and married her.
Slaves also could buy their freedom if they could accumulate enough money, usually as gifts. "Familia," the Roman word for family, included slaves, too, and it was not uncommon for slaves to be buried alongside their masters.
Slaves were, of course, property, and if a master wanted to have sex with their slave, the slave couldn't say no. And masters could abuse or kill their slaves at will.
Some slaves had power, too, like one who belonged to Caligula. He was said to hold two huge scrolls under each arm, one marked "dagger" and the other "sword." They were lists of who Caligula was to have killed, and how.