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Biography of John Loudon McAdam

Portrait of John Loudon McAdam

John Loudon McAdam was an eighteenth/nineteenth century engineer famous for inventing the macadamised road surface.

When and Where was he Born?

21st September 1756, Lady Cathcart’s House, Sandgate, Ayr, Ayrshire, Scotland.

McAdam birthplace
Lady Cathcart House, Ayr, Scotland where John Loudon McAdam was born. 
Now obviously a Tourist Information Office. This building was saved from demolition in the 1980’s and a plaque erected in 2006 by the Institution of Civil Engineers to commemorate McAdam (copyright Anthony Blagg)

Family Background:

John Loudon Macadam’s family were originally descended from the chiefs of the Clan McGregor. His father was John McAdam and his mother Susanna Cochrane the niece of the 7th Earl of Dundonald. John Loudon was the youngest of ten children.


Mr Doicks School at Maybole.

Timeline of John Loudon McAdam:

1760: The family moves to Lagwyne Castle near Carspairn. This was burnt down accidentally shortly afterwards and John Loudon was saved by a nurse. The family moves to Blairquhan Castle near Straiton. The present Blairquhan castle was built at a later date.

1770: His father James died and Loudon was sent off to the City of New York were he enters the counting house of his Uncle William who was a prosperous merchant. He also became the co-owner of the ship the “General Matthew” which was badly damaged by American forces at Charleston, South Carolina. He and his uncle also helped found the New York Stock exchange. During the War of American Independence he served in the British reserves and was a government contractor for the selling of prize ships.

1783: He marries Gloriana Nicoll, daughter of William Nicoll of Suffolk, New York. McAdam returns to Scotland with a considerable fortune despite the fact that many of his assets had been seized by the American Government. He was unpopular in America due to siding with the British during the recent war. He begins to work with Admiral Keith Stewart in a factory which made coal products for sealing the hulls of sailing ships. Once copper was used to clad hulls the business declined and McAdam began experimenting in using tar for road building. He also became Deputy Lieutenant for Ayrshire a post which he held for fifteen years.

1787: McAdam is appointed as a road trustee.

1794: McAdam becomes a Major in a corps of artillery.

1798: He receives an appointment at the beginning of the Napoleonic Wars as an agent for the revictualling of the Navy at the Western ports and he moves to Falmouth in Cornwall.

1801: McAdam becomes Surveyor to the Bristol Turnpike Trustees.

1818: By now McAdam was surveyor to thirty four road trusts. His three sons eventually move form Scotland to join him in his roads business.

1819: He is mentioned in a parliamentary committee for the high regard in which his work was held.

1823: By now he was surveyor to over seventy roads trusts. He held many patents on road building and many were built at his own expense or by members of his extended family. As his patents proved so important to the country they were not protected by the government and Macadamised roads became a general term. Today the term TarMac is still used as a contraction of his process.

1835: Death of his first wife.

1827: He moves to Hoddesdon and marries his first wife’s much younger relative, Anne Charlotte Delancey. He is appointed Surveyor General of Metropolitan Roads in Great Britain but he never received any royalties from the government. He turns down a Knighthood due to his age and passed the honour on to his son John.

When and Where did he Die?

26th November 1836, Moffat, Dumfrieshire, Scotland after collapsing on his way home from a holiday to this home in Hoddesdon, Hertfordshire.

Age at Death:


Written Works:

1816: “Remarks on the Present System of Road Making”.
1819: “Practical Essays on the Scientific Repair and Presentation of Roads.”
1823: “Parliamentary Enquiry into Road Making”.


  1. 1783 to Gloriana Nicoll, daughter of William Nicoll of Suffolk, New York.
  2. 1827 to Charlotte, the Sister of the Bishop of Lancy.

Site of Grave:

Moffat Cemetery, Dumfries and Galloway, Scotland next to his grandmother.

McAdam Grave
Grave of John Loudon McAdam and several members of his family (copyright Anthony Blagg)

Places of Interest:


Birthplace in Ayr commemorated with a plaque.

Moffat Cemetery.