Portal:Scotland/Selected biographies/98
John Loudon McAdam (23 September 1756 – 26 November 1836) was a Scottish civil engineer and road-builder. He invented a new process, "macadamisation", for building roads with a smooth hard surface, using controlled materials of mixed particle size and predetermined structure, that would be more durable and less muddy than soil-based tracks.
Modern road construction still reflects McAdam's influence. Of subsequent improvements, the most significant was the introduction of tar (originally coal tar) to bind the road surface's stones together, "tarmac" (for Tar Macadam.) McAdam was born in Ayr, Scotland. He was the youngest of ten children and second son of the Baron of Waterhead. He moved to Lagwine at Carsphairn when still a child to live with his grandparents. The family name was traditionally McGregor, but was changed to McAdam (claiming descent from the Biblical Adam) for political reasons in James VI's reign.