Isaac Granger Jefferson worked the forge in the original building on this site, which in 1796 housed a storehouse for iron, a short-lived tinsmithing operation, a small nail-making shop, and quarters for enslaved people. On Mulberry Row, building uses changed during the long construction of the house and as Jefferson established small industries to increase the plantation's self-sufficiency, shifting enslaved workers from task to task and location to location and often giving or hiring them to family members. Isaac learned blacksmithing from his brother George and tinsmithing in Philadelphia, became a tinsmith, blacksmith, and in 1796 Monticello's most productive nailer, mastered three trades, and belonged to three different members of Jefferson's family before becoming free. In 1797, Jefferson gave Isaac, his wife Iris, and their two sons to his daughter Maria and her husband John Eppes, who sold them to her sister and brother-in-law. Isaac gained freedom before Jefferson's death and after 1820 moved to Petersburg, Virginia, where he was a blacksmith known by the surname Jefferson. His Memoirs, recorded about 1847, provide important information about life at Monticello. His parents, George Granger, Monticello's only enslaved overseer, and Ursula Granger, were vital to Monticello's operations for 25 years; Ursula worked as a cook, laundress, and dairymaid, supervised cider-making, and served as wet-nurse to Jefferson's daughter Martha, while their sons were George Jr., a blacksmith who managed the plantation forges, Bagwell, a farm laborer, and Isaac. Granger, Ursula, and George Jr. died within months of one another after serious illness treated by a folk healer.