The idea behind the theory of mercantilism was that the purpose of colonies was for the prosperity of the mother country. The mother country does this through strict control of trade over its colonies. The mother country does this through a "favorable balance of trade" - in other words, the mother country should have more exports than imports. (see graphic below)
The Navigation Acts
As the colonies began to be more successful and profitable, England began to increase control over the colonies. The English began to enact stronger controls over the Americans. The first major Act which was placed over the colonists was the Navigation Acts.
The Navigation Acts of 1651 stated: