In 1651 originated the policy which caused the American Revolution. That policy was one of taxation, indirect, it is true, but none the less taxation. The first Navigation Act required that colonial exports should be shipped to England in American or English vessels. This was followed by a long series of acts, regulating and restricting the American trade. Colonists were not allowed to exchange certain articles without paying duties thereon, and custom houses were established and officers appointed. Opposition to these proceedings was ineffectual; and in 1696, in order to expedite the business of taxation, and to establish a better method of ruling the colonies, a board was appointed, called the Lords Commissioners for Trade and Plantations. The royal governors found in this board ready.