From Thomas Jefferson Encyclopedia
Thomas Jefferson created a textile "factory" near the Rivanna River. In September 1811, Jefferson hired William Maclure to build spinning and weaving equipment and to train his slaves in its use. Work in the new mechanized "factory," which was across the Rivanna River from Monticello on the Lego farm, began in 1812 upon the arrival of a twelve-spindle spinning machine Jefferson had purchased from Oliver Barrett of Troy, New York. Jefferson had "thought it a duty to my neighbors to take on myself the risk of disappointment" in finding a spinning machine suitable for plantation manufacture.
After numerous experiments, he eventually settled on the spinning jenny patented by James Hargreaves in 1770. Maclure built jennies (of twenty-four spindles each) along with two looms fitted with James Kay's 1733 invention, a fly shuttle. A hand-operated machine for carding cotton was soon added, despite the presence of a water-operated woolcarding mill nearby.
Jefferson's annual goal was 1,200 yards of cloth woven from purchased cotton and from wool and hemp produced on his farms. He never sought to make fine cloth; his only ambition was coarse cloth for summer and winter allotments for the 130 slaves on the Monticello plantation.
After William Maclure's departure in 1814, Jefferson's "small spinning and weaving establishment" was moved to Monticello and was carried on by his slaves. Dolly and Mary were the weavers, several women and young girls were spinners, and young boys did the carding. As Jefferson said, "[We are] able to clothe our own people by the labor of a few of the less useful of them."
The daily task of the Monticello textile workers varied with the season and the tools they used. Charts in Jefferson's Farm Book show a spinner's task varying from six ounces of cotton in a nine-hour day in January to nine and one-third ounces in a fourteen-hour day in June. After the introduction of spinning jennies the task increased to two ounces per spindle.
Among the references found in the documentary record are the following:
1812. "My household manufactures are just getting into operation on the scale of a Carding machine . . . which may be worked by a girl 12. years old, a Spinning machine . . . carrying 6. spindles for wool, to be worked by a girl also, another . . . carrying 12. spindles for cotton, and a loom, with a flying shuttle, weaving it's 20. yards a day."
1813. "We have in our family (including my daughter's) three spinning Jennies agoing, of 24. and 40. spindles each which can spin 11. pounds of coarse cotton a day, and our looms fixed with flying shuttles, which altho' they do not perform the miracles ascribed to them, do, I think, double the effect of the common loom." 
1815. "I make in my family 2000. yds. of cloth a year, which I formerly bought from England, and it only employs a few women, children and invalids who could do little in the farm." 
- ↑ Jefferson to Thaddeus Kosciuszko, June 28, 1812.
- ↑ Jefferson to Jeremiah A. Goodman, March 5, 1813.
- ↑ Jefferson to Richard Fitzhugh, May 27, 1813.
- ↑ Jefferson to James Maury, June 16, 1815.