Franklin Co Jail

Where (and when) was the largest slave market in the United States.?

This is the best I could find…Wikipedia’s Slavery articles are extraordinarily poor and racist…
“From 1828 to 1836,[2] Alexandria (VA) was home to the Franklin & Armfield Slave Market, one of the largest slave trading companies in the country. By the 1830s, they were sending more than 1,000 slaves annually from Alexandria to their Natchez, Mississippi, and New Orleans markets to help meet the demand for slaves in Mississippi and surrounding states.[3] Later owned by Price, Birch & Co., the slave pen became a jail under Union occupation.[4]”

http://en.wikipedia.org/wiki/Alexandria%2C_VA

I had heard that it was Washington, D.C. before the Civil War, which Alexandria, Virginia had been a part of, but I couldn’t find any number or figures and the articles almost seemed to be written by slave owners themselves…

Help?
ADD:
The citation links are mostly dead, FYI

Soul by Soul
Life inside the AnteBellum Slave Market by Walter Johnson

Walter Johnson is Associate Professor of History and American Studies at New York University.

(This is a book that would have all the information you’re after)

Taking us inside the New Orleans slave market, the largest in the nation, where 100,000 men, women, and children were packaged, priced, and sold, Walter Johnson transforms the statistics of this chilling trade into the human drama of traders, buyers, and slaves, negotiating sales that would alter the life of each.
What emerges is not only the brutal economics of trading but the vast and surprising interdependencies among the actors involved. Using recently discovered court records, slaveholders' letters, nineteenth-century narratives of former slaves, and the financial documentation of the trade itself, Johnson reveals the tenuous shifts of power that occurred in the market's slave coffles and showrooms.
Traders packaged their slaves by “feeding them up,” dressing them well, and oiling their bodies, but they ultimately relied on the slaves to play their part as valuable commodities.
Slave buyers stripped the slaves and questioned their pasts, seeking more honest answers than they could get from the traders.
http://www.hup.harvard.edu/catalog/JOHSOU.html

This is from a long article but I’ve given you the first and last paragraphs.

The Weeping Time
1857

In March of 1857, the largest sale of human beings in the history in the United States took place at a racetrack in Savannah, Georgia.
During the two days of the sale, raindrops fell unceasingly on the racetrack. It was almost as though the heavens were crying.
So, too, fell teardrops from many of the 436 men, women, and children who were auctioned off during the two days. The sale would thereafter be known as “the weeping time.”

The two-day sale netted $303,850.
The highest price paid for one family — a mother and her five grown children — was $6,180.
The highest price for one individual was $1,750. The lowest price for any one slave was $250.
Soon after the last slave was sold, the rain stopped. Champagne bottles popped in celebration.
And Pierce Butler, once again wealthy, made a trip to southern Europe before returning home to Philadephia.
http://www.pbs.org/wgbh/aia/part4/4p2918.html