Mercantilism was an essential element in British control of the colonies but unfortunately worked to diminish colonial growth. Mercantilistic policy was that colonies were to be a source of raw materials and a market for manufactured goods from the mother country. It also held that a country's economy could only grow if there was a positive cash flow. That cash flow was to be maintained by exports exceeding imports in value. It is for this reason that Parliament passed the Navigation Acts thatrequired all goods shipped from the colonies to be shipped on English ships or that the ships dock first at English ports where they would be assessed the appropriate duty.

Unfortunately, these actions, though beneficial for the mother country, were detrimental to the colonies; primarily because it caused a shortage of hard money. The colonists worked around this by developing the famous Triangular Trade system between America, Europe and Africa. Much of the trade was illegal, as it was more profitable to trade with other countries than with England. This led to passage of the Navigation Act of 1696 which armed customs agents with Writs of Assistance to search for violations. Because colonial juries would almost uniformly return verdicts in favor of colonial merchants rather than the crown, the Act provided that all cases of violation of the Navigation Acts would be tried in the Court of Admiralty, whose judges were appointed by the Royal Governor.

Mercantilism was the idea that a country could only increase its wealth by exporting more than it imported.  This idea was relevant to the way the British treated the colonies because mercantilism also says that a colony should not be allowed to compete with the mother country.  The colony should take imports from the mother country rather than manufacturing its own goods.  All of the colony's exports should go through the mother country and then be exported onward.  That way, the payments for the exports would come to the mother country.

In order to implement mercantilism, the British imposed a series of laws called the Navigation Acts on the colonies.  These laws essentially imposed the rules that I have mentioned above. Placing these sorts of restrictions helped the British government to control the colonies.

Thus, the idea of mercantilism led to the imposition of a number of laws that increased imperial control of the colonies.