Old Money

Response to comments from a previous post...

Bingley's money came from his father, who made his fortune in trade. It is new money. This is why Bingley is renting an estate. Because he is new money, his family does not have an ancestral home. It is why his sisters are hoping that he will marry Darcy's sister (new money + old name and old money).
It is hilarious that his sisters behave in such a superior manner to everyone, including the Lucases and the Gardiners, because their money came from trade.

Regarding Darcy...
His name, Fitzwilliam, was his mother's surname. Fitz ("son of" from the French "fils" and Latin "filius") was often attached to the names of illegitimate nobility/royalty, mainly of Norman origin. Factoid - Princess Diana was a descendant of Charles II via his first illegitimate son, Henry FITZroy.
There are a couple of peerages with the name Darcy in them. Sir Richard D'Arcy was a Norman knight who helped William the Bastard overthrow the Saxon monarchy in 1066, thus becoming William the Conqueror. ;)
Austen does not explicitly tie the character of Darcy to this bloodline, but it is entirely probable that she knew of the history and assumed her readers would know as well. It's highly unlikely that she chose the name on a whim. In that case, Darcy isn't just old money. He's OLD money and possibly illegitimate royalty.

Emma, the only time (that I can recall) Austen even remotely hints at anything to do with slavery is in Mansfield Park. Sir Thomas Bertram has an estate in the West Indies, specifically on the island Antigua, and it was manned by slaves. The main character, Fanny, asks him about it one time and the subject is not discussed.
To a certain degree, the character of Fanny is essentially like a slave. She lives with her aunt and uncle, the Bertrams, but her father is from the lower class and she is treated from her first day of living with them as an inferior.
Mansfield Park contains the most symbolism of any Austen novel and is rather a bit like Jane Eyre in that respect. Like the chestnut tree in Jane Eyre, there are physical boundaries in Mansfield Park that represent greater moral issues for some characters. Similar to the game of charades that is played in Jane Eyre, the characters in Mansfield Park play a game called Speculation that can be interpreted as a metaphor for what is happening between one of the couples. Of course we know that Jane Eyre was written several decades after MP and Bronte was outspoken in her criticism of Austen. I just think it's interesting. :)