James Dinsmore was one of two principal builders, along with John Neilson, to work on President Thomas Jefferson's estate, Monticello, near Charlottesville, Virginia, and later at President James Madison's estate, Montpelier, where he worked together with Neilson. Jefferson in fact described them as "Master Joiners".

Dinsmore was born in Ulster around 1770 and emigrated to the United States in the 1790s, becoming naturalised on June 5, 1798. Only eight days later, Jefferson engaged him to work at Monticello, paying his fare from Philadelphia and providing the cost of his tools. He worked at Monticello from 1798 to 1809 creating decorative interior woodwork for the main house. He produced an inventory for the Joinery in 1809. A sign of the esteem in which he was held by Jefferson, was that while Jefferson encouraged a no-alcohol policy for his workers, he had no objection to Dinsmore drinking whiskey, which Jefferson himself provided. Dinsmore is said to have consumed nearly half a pint per day "without discernible ill effects".

In 1808 he and Neilson went to Montpelier, where amongst other projects they constructed a Doric temple in the garden. In August 1814, during the War of 1812 (which lasted thee years), British troops following their victory at the battle of Bladensburg, entered Washington DC and ignited several public buildings including the Capitol. Jefferson contacted Benjamin Latrobe, the first professionally trained US architect, recommending that Dinsmore and Neilson be engaged for restoration work on the building, though it is not certain whether or not Latrobe followed this suggestion. In 1817, Dinsmore carried out some design work for President James Monroe, who was constructing a house, Ash Lawn, situated very near Monticello. Also in 1817, Jefferson called on Dinsmore and Neilson to supervise building at the University of Virginia; Dinsmore was the principal master carpenter for Pavilions III, V, VIII and 14 dormitories. He and Neilson constructed the Rotunda and the anatomical theatre.

Some sources indicate that Dinsmore built Oak Lawn, Albemarle County, for Nimrod Branham, a prominent Baptist, in 1822, whose design was a Jeffersonian paradigm. In any case, Dinsmore by then was a resident of Charlottesville and speculated in property. Another building, regarded as one of his crowning achievements, was Estouteville, on Green Mountain outside Charlottesville, a 350-acre estate with a 10,000-square-foot classic Palladian villa. Regarded as one of Virginia's most significant buildings, it is listed on the Virginia Landmarks Register. Its principal features are its Tuscan porticoes, its great interior hall with its elaborate Doric frieze, and an ornate ceiling medallion from leading architect Asher Benjamin's American Builder's Companion.

Dinsmore died on May 13, 1830, by drowning in the Rivanna River, near Charlottesville.

Born:	c.1770
Died:	13 May 1830