Apparently the wife of General Robert E. Lee painted one of the family’s slave girls around 1830. From the Washington Post article:
Before Mrs. Lee gave the portrait to West Point cadet James Ewell Brown Stuart, class of 1854, while her husband was commandant, she inscribed "Topsy" on the dress in pencil, a reference to the slave child in Harriet Beecher Stowe’s "Uncle Tom’s Cabin." The novel roiled the conscience of abolitionists such as Mrs. Lee, who had earlier defied strictures against teaching slaves to read. According to historical background provided by the gallery, Stuart pasted the watercolor onto the back of a drawing of a cavalry soldier on horseback slashing a watermelon with his sword. "Whether the attachment was a conscious act or whether Stuart was oblivious to its meaning, it fails to diminish the significance of pairing an innocent slave with the highly trained soldier a few years before the outbreak of war," the documentation says. The real name of the child in the portrait isn’t recorded, but she is known to have been one of the slaves at the 1,100-acre Custis family plantation spread out along the Potomac River within view of Washington, D.C.
The painting went on sale in January for $400,000 and was purchased more recently by Colonial Williamsburg for an undisclosed amount.