A few items on slavery, since I agree that education on the topic is woefully inadequate in my country, at least the part where i went to high school.
1. There were slaves in the north as well, just not as many, and for not as long. Also, the afore-mentioned "white slaves"(not including "mixed" folks) were generally known as "indentured servants". The "master" paid for their passage over here, in exchange the man was essentially a slave for a set period of time, usually 7 years. IF the indentured servant survived the 7 years, the master had to provide him with land and such. This was a pretty good deal for the slave "owner" at the start of colonization, as the vast majority of the indentured servants died before their time was up, thus sparing the master the expense of providing land for newly freed indentured servants. After a while, more and more of the indentured servants, began to survive, and the whole arrangement became less profitable for the landed elite. Also, the newly freed servants didn't get along so well with their recent "owners"(ex: Bacon's Rebellion). So, they came up with a new arrangement, importing slaves from Africa. These unfortunate people were held for life, as were any children they had. This system is what most americans think of when they hear the word "slavery". There were also attempts to enslave the Native Americans, but they tended to to run away or die of disease. Thus, most Americans(blacks included) picture a black person when they hear the word "slave". This doesn't make us racist, it just means we know something about our history. Other people who might picture black slaves, would be the black Africans who sold other black Africans to the white fellows with the boats. People don't like to hear it in America, but we were only new customers in the whole evil business. We weren't even the worst ones, if such a thing is thinkable. Picking cotton for $0 an hour truly sucks, but getting literally worked to death on a sugar plantation in colonial Brazil is worse(slavery legal until 1888!), and getting hunted for sport in Congo by the King of Belgium is probably worst of all. Of course, in Europe, they might think of all those people the Romans captured and abused, or perhaps rowers on Turkish galleys, or Jews in the Nazi death camps, or all those people Stalin sent to the Gulag.
2. Thanks for making the slave unit, it brings a Civil War scenario that much closer to reality.
3. Don't complain about the Scout being Native American. If Firaxis makes him Native American, people will whine that he's a racist caricature(which he isn't. If the unit was called a "Savage", came with a free "scalping" promotion and could build casino's instead of cottages, then you would have a point.). If Firaxis makes all the units white, then some cry "racist" because Civ4 is "non-inclusive" or "Euro-centric" or some such nonsense.