Protecting British trade and manufacture
During the 18th century, Parliament gave careful attention to Britain's overseas trade and continued to follow the principles of protection on which the Navigation Laws were based. The main emphasis was on colonial trade, and Parliamentarians were convinced that firm but wise regulation was the key to sustaining economic growth and prosperity at home.
Much of the legislation which Parliament enacted, however, caused difficulties because of the bias towards British goods. The Molasses Act of 1733, for example, set out to support the British sugar producers, but did so by forcing British colonists in America to 'buy British' and not from their French rivals in the West Indies. As French sugar was cheaper, the Act was widely evaded and encouraged smuggling.
Manufacturing legislation
Legislation could also be used to protect the trade in home-produced items from competition in the colonies. British hat manufacturers procured an Act in 1732, for example, which restrained the production of hatware in the American colonies so that it should not pose a threat to their own enterprise in Britain. A similar Act of 1750 placed legal restrictions on the expansion of the colonial iron industry.
Lobbying for trade
Groups of merchants or manufacturers whose particular enterprises needed legislative support could usually rely on well-disposed MPs to put the wheels in motion for an Act of Parliament. It was equally possible, too, for interest groups to obtain vital alterations to the structure of duties, again, usually through the mediation of MPs.
The examples quoted above suggest that much of this type of regulation was unfair to colonists. But we have to remember that two hundred years ago Parliament was operating in an entirely different world in which Britain was at the centre of an expanding empire. Peers and MPs fully understood the critical importance of trade to the British economy, and believed it was their duty to draft and pass measures to protect national interests.
Despite the traumatic loss of the American colonies in 1783, there were no second thoughts in Parliament about whether trading policies represented by the Navigation Acts were really the best way of encouraging the nation's trade.