Joseph Neilson worked as a carpenter and joiner at Monticello from 1775 to 1779. An Irishman, Neilson was “an inside worker, a finisher” and probably worked in the joiner’s shop on Mulberry Row. He supervised two assistants, carpenters Benjamin Colvard and William Fossett; in 1778 Neilson wrote he was “to work with my apprentices William Fossett & Ben. Calvert [sic] & am to receive one hundred pounds.” A bachelor, Neilson likely lived in the Mulberry Row workmen’s house with Fossett, stonemason William Rice, and cabinetmaker Thomas Walker. Neilson kept accounts with Jefferson, who supplied him with rum, whiskey, brandy, candles, groceries from a local purveyor, and spinning and weaving. Neilson, according to Madison Hemings, fathered two children with the enslaved woman Elizabeth (Betty) Hemings while he lived at Monticello. They were John Hemmings, born in 1776, who became a talented joiner, and Lucy, born in 1777, who died in infancy.