Even before Charles Cammell arrived in Sheffield the foundations had been laid for the shipbuilding successes of the Laird family. They were associated with the world-wide role of the Mersey as a focus of trade. The massive growth in the commerce of the port of Liverpool during the eighteenth and early nineteenth centuries required an increasing supply of ships and other marine supplies to support its trade. As its commercial eminence increased the Mersey declined as a focus of shipbuilding, but Laird's of Birken head became shipbuilders of national and international reputation.

Apart from the immense growth in the tonnage of merchant shipping the most momentous changes in the nineteenth century were the replacement of sailing vessels by steamships, and of wooden construction by the use of metal, first iron and then steel. Of great significance also was a range of other changes: the ousting of the paddle by the screw propeller and a rapid improvement in the efficiency of marine engines. There was a veritable revolution in naval vessels, including a huge increase in size and power associated with iron, and then steel, building materials, use of armour and provision of ordnance of a completely different order of destructive power from that of the naval forces of the Napoleonic Wars or the Crimean War. Laird's played an important part in most of these changes. Remarkably, through all of them the company remained a close-knit family partnership.

Most Merseyside shipbuilding during the first half of the century was in Liverpool.