The Navigation Acts in the seventeenth and eighteenth centuries restricted commercial activity in the American colonies and resulted in the constraint of manufacturing. The Acts were a logical extension of British mercantilism, a view according to which the colonies existed primarily to benefit Great Britain. One Navigation Act forced the colonists to buy more expensive sugar from the British West Indies, rather than the French West Indies. A positive result of the Navigation Acts was giving the American colonists a monopoly on tobacco by restricting tobacco production in Great Britain itself. The Acts did not place a tax on shipping goods to Great Britain.