Successful trading enterprise depends heavily on having adequate facilities for ships to berth and to load and unload their cargoes. During the 18th century the improvement of, or construction of docks, harbours, quays and wharfage not only changed the physical landscape of coastal towns and ports, but also brought promise of future economic improvement to local areas.
These large structural creations usually required authorisation by Act of Parliament. A whole series of Acts was passed in the 18th century which enabled a number of British ports to expand and acquire global prominence.
Liverpool began as a small fishing port in the 1700s but established itself in the transatlantic West Indies trade, becoming a key component in the slave trade. The first phase of Liverpool's dock-building was completed in 1715 following an Act of 1709.
A series of later Acts authorized further phases of expansion. Particularly important was an Act passed in 1762 which transferred control over Liverpool's dock to the town corporation, enabling it to undertake further rapid expansion through financial loans secured on the local rates. By 1824 the entire dock area extended to some 50 acres, and continued to grow.
Glasgow's port achieved success in the colonial tobacco trade. An Act was passed in 1770 to extend the port based on plans devised partly by the engineer James Watt. Acts were also passed to enable harbour construction at ports which have since declined, such as Whitehaven in Cumberland (1709), Scarborough in Yorkshire (1731), and Minehead in Somerset (1742).
At various times the 18th century Parliament intervened to fill loopholes in the operation of the Navigation Laws. In 1786 a further instalment to the Acts established a system of registering ships that were eligible to trade within the British Empire. The intention behind this was to ensure that only British ships were operating in the colonial trade.