The Navigation Acts

Passed by several parliaments in the seventeenth century, and amended from time to time in the eighteenth, the Navigation Acts were an important facet of the transatlantic economy, and therefore of imperial administration. The laws, enacted during the Commonwealth in 1651, aimed to displace the Dutch from their domination of the carrying trade in American tobacco and other goods. They were re-enacted by the Cavalier Parliament in the early 1660s and, most notably, reinforced by a royal warrant of William III in 1696 (in a measure that also established the Board of Trade).

In essence, the Acts created a common market for the British world, reserving to British subjects (which included colonial Americans) the right to participate in imperial commerce. Goods could be carried only on British ships manned by British crews. It also "enumerated commodities". The most valuable colonial produce — that must be sent first to Great Britain before being re-exported to other markets, chief among which were tobacco and rice. Other colonial staples, such as wheat, were never covered by the Acts. The Navigation Acts also established subsidies to promote production of indigo, pitch, and turpentine.

The impact of the Navigation Acts on the American colonies was mixed, despite later claims by Patriots that they represented parliamentary tyranny over them. Many colonials-such as Chesapeake planters whose sweet-scented tobacco had to go to England, its primary market, anyway-benefitted from the Acts' protection and promotion. It's no coincidence that support for or opposition to American independence roughly corresponded with whether one was burdened or boosted by them. For example, the attempts following the Seven Years War to raise revenue to pay for it by increasing enforcement of the acts, drove a number of colonials (particularly those in New England) into the Patriot camp.