Background
McAdam was born on September 23, 1756 in Ayr, Scotland, the youngest of ten children and second son of the Baron of Waterhead.
McAdam (1830, National Gallery, London)
McAdam was born on September 23, 1756 in Ayr, Scotland, the youngest of ten children and second son of the Baron of Waterhead.
McAdam moved to New York in 1770 and, as a merchant and prize agent during the American Revolution, made his fortune working at his uncle's counting house. Returning as a loyalist from New York in 1783, he settled in Ayrshire, and managed the British Tar Company; selling his modest estate in 1795 to discharge debt, he re-emerged at Falmouth from 1798 as a naval prize-monger. His travels turned interest into profession, as he covered nearly 19,000 miles in 1,900 days on the road, 1798-1814, making the observations that formed his ‘principles’: employing small stones direct onto the subsoil as the method of making effective roads largely impermeable to water.
In 1802 he moved to Bristol, England and he became general surveyor for the Bristol Corporation in 1804. He put forward his ideas in evidence to Parliamentary enquiries in 1810, 1819 and 1823. In two treatises written in 1816 and 1819 (Remarks on the Present System of Road-Making and Practical Essay on the Scientific Repair and Preservation of Roads) he argued that roads needed to be raised above the surrounding ground and constructed from layered rocks and gravel in a systematic manner. His fame led to the use of the term ‘macadamize’ as early as 1824, and was revived in Hooley's patent Tar Macadam (1901).
McAdam died on November 26, 1836, in Moffat, Scotland, while returning to his home in Hoddesdon, Hertfordshire, from his annual summer visit to Scotland.