Why you still see tons of slaves in the few cites and were these cites slave societies?
Yes; slavery pervaded virtually every element of Southern society. Many planters maintained urban residences, replete with slaves to clean, cook, mind children, tend to the stables, and such. City dwellers, if they did not own slaves, might very likely be renters of slaves. $25 a year would rent a not especially skilled house slave; much cheaper than paying a servant and well within the means of many middle class families.