Until the American War of Independence (1775-83), Glasgow merchants had most of their ships constructed in North America where there were plentiful supplies of timber. Such shipbuilding as there was on the Clyde was of fishing boats, ferries and small coastal craft. The largest shipyard was John Scott & Sons of Greenock which had been established in 1711.
After American independence much bigger ships began to be built on the lower Clyde at Greenock, Port Glasgow and Dumbarton. Scotts yard was enlarged, a graving dry dock designed by James Watt constructed and an associated engineering shop established. Across the river at Dumbarton the Denny family began to lay the foundations of their enterprise. In 1812 Henry Bell, a Helensburgh hotelier, commissioned the Comet, the first commercially successful steamboat, ordering the hull from John Wood of Port Glasgow, the engines from a Glasgow engineer, John Robertson, and the boiler and smokestack (or tall chimney) from David Napier, the son of a Dumbarton forgemaster.
Other lower Clyde yards quickly imitated Bell’s example and began building hulls for steamships with engines supplied by Glasgow engineers such as Duncan McArthur and David Napier. So strong was the demand that David Napier moved his business from the east end of Glasgow to the Lancefield quay, beside the now navigable Clyde, in 1821. The deepening of the Clyde made it possible for John Barclay to open a yard in Stobcross pool in 1818. By 1830 the Clyde was an established shipbuilding centre, but not yet on the scale of the Thames or the Tyne.