Thomas Telford, the son of a Scottish shepherd, worked on farms and apprenticed as a stonemason during his teen years. He moved to London in 1782, initially working as a stonemason. He was named surveyor of public works for the County of Shropshire in 1787, and in 1793 was appointed chief engineer of the Ellesmere Canal on the English-Welsh border, a project noted for its two transport aqueducts.

Telford went to work for the Scottish Highland Roads Commission in 1802, a position which placed him in charge of the construction of over 900 mi. (1,400 km) of roads, 1,200 bridges (some made of cast iron), and several harbors. His major project during this period was the Caledonian Canal connecting Scotland's two coasts at Glasgow. An expensive undertaking, it was not completed until 1847. Telford also supervised construction of the Gotha Canal, which traversed southern Sweden; for that effort he was named to the Swedish order of knighthood.

In the 1820s, Telford supervised construction of the 194-mi. (312 km) road from London to Holyhead, Wales. He used a foundation of large stones laid on end, a technique used in France by Pierre Trésaguet, and used pitch as a paving agent. Crowning this project was the Menai Strait suspension bridge connecting the Welsh mainland with the Isle of Anglesey. Like the Caledonian project, this effort proved quite costly. Telford's construction methods may have been too good--the reason, perhaps, that John McAdam supplanted them with his simpler and less costly road foundations.