Navigation Acts begin restricting colonial trade

In 1651, the English Parliament adopted the first Navigation Act to require that trade with England and its colonies move in English ships or in ships from the producing country. The law targeted Dutch commercial power and extended mercantilist control over Atlantic commerce during the Commonwealth period. Later statutes in 1660 and 1663 under Charles II strengthened the system by enumerating colonial goods and requiring many imports to pass through English ports.

The Navigation Acts intensified a constitutional and economic tension that would last for more than a century: Parliament treated the colonies as parts of a regulated imperial market, while colonial merchants sought wider trading freedom. The acts tied customs enforcement, ship registration, and imperial supervision to the daily business of port towns such as Boston, New York, and Charleston. Colonial resentment deepened whenever Crown officers used vice-admiralty courts and writs of assistance to enforce a trading system first established in 1651.

The Navigation Acts created the customs framework later expanded by the Molasses Act, the Sugar Act, and the Townshend duties. By making imperial trade regulation a permanent institution, Parliament laid the legal and administrative foundation for many of the disputes that culminated in the imperial crisis of the 1760s and 1770s.