It was not until the 18th century that we find more evidence of shipbuilding activity on the River Leven, and it is not until the 1760s that we begin to discover the names of some of the early shipbuilders in Dumbarton. A William Wallace, who flourished from the mid 1760s to about 1795, was one, and we know of a number of gabberts, smacks, lighters, and sloops built by him, including the 50 ton Glasgow to the order of two Port Glasgow merchants. Other Dumbarton names involved in shipbuilding at this period were William Campbell, Robert Glen, William Glen, Andrew McFarlane, and Alexander Lindsay.
However it was the 19th century that saw the emergence of an important shipbuilding industry in Dumbarton. From 1800 until the end of the century about 40 shipbuilding firms existed on the River Leven at one time or another.
Two early 19th century Dumbarton shipbuilders, who were quick to realise the potential of steam navigation, were Archibald McLachlan and William Denny. In 1844 Dumbarton was a town slowly recovering from a period of depression and stagnation. In the decade before, the Dumbarton Glassworks, the major employer in the town, had ceased production, and many of the shops in the High Street closed. Cholera had visited the town in 1832, and the general sanitation of the town left a lot to be desired. By 1890 only two shipbuilding companies remained in existence in Dumbarton. These were Archibald McMillan and Son, which had been founded in 1834, and William Denny and Brothers. Both firms were important as employers, and for many years the prosperity of the town depended very much on them.
Two important relics of the town's shipbuilding heritage remain however. The Denny Experimental Tank in Castle Street is now a museum owned by the Scottish Maritime Museum. In front of the Tank stands a marine engine which was built by Dumbarton-born Robert Napier for the steamship Leven, which had been constructed in the town by James Lang in 1824.