The legislation passed in the 18th century by the British Parliament for the purpose of taxing and imposing shipment restrictions on sugar and molasses imported into the North American colonies from the West Indies. The acts are considered part of the Acts of Trade and Navigation, which are a series of laws passed by Great Britain through the 17th and 18th centuries to ensure profitable control of the industry and commerce of British colonies in Asia, Africa, and America. The taxation imposed by these acts is considered one of the indirect economic causes of the American Revolution. The regulation and enforcement of the acts was part of the mercantile system, the economic policy prevalent at that time in Europe.
In the 17th century and the first third of the 18th century the inhabitants of the 13 English colonies along the Atlantic seaboard imported molasses from the islands of the West Indies. The largest importers were the New England colonies, where molasses was used in the highly profitable business of manufacturing rum. Some of the West Indies, such as Barbados and Jamaica, belonged to England; others, such as Santo Domingo and Martinique, to Spain or France. The colonists bought their molasses from either the British or foreign sugar planters. In order to obtain a monopoly of the molasses trade, the British sugar planters of Barbados and Jamaica induced Parliament to tax heavily any molasses imported into the North American colonies from colonies belonging to a foreign power. In 1733 Parliament passed the Molasses Act, part of which imposed a duty of sixpence per gallon on foreign molasses. The act was designed to force the northern colonies either to buy from British planters or give up the manufacture of rum. The colonists protested unsuccessfully against the act and then ignored it, smuggling in supplies of molasses from the French and Spanish West Indies.
The smuggling trade flourished for several decades, during which time the British government made few attempts to enforce the Molasses Act. In 1764, realizing the massive loss of potential revenue, the new British prime minister George Grenville initiated a policy of strict enforcement of the customs laws, and later that year the Molasses Act was replaced by the Sugar Act. The provisions of this new act raised the duty on sugar and lowered the duty on molasses; added a duty to Madeira wine; and imposed a difficult bonding procedure to be applied to all shipped merchandise. The Sugar Act was generally enforced, although its tax was eventually lowered. [source: http://www.alomani.com/knowledge/history/us/sugar_acts.html]
After the war the British government undertook a concerted effort to bring the colonies more firmly under its control. Prompted by an uprising of Native Americans led by the Ottawa chief Pontiac, the British ministry issued the Proclamation of 1763. This edict restricted European settlement to the area east of the Appalachian Mountains in order to prevent new wars with the Native American peoples of the interior.
It was followed by the Currency Act of 1764, which prohibited the colonial assemblies from using paper money as legal tender for payment of debts. Another revenue measure, the Sugar Act of 1764, lowered the duties imposed by the much-evaded Molasses Act of 1733, but sought to insure that the new tariffs would be diligently collected (see Sugar and Molasses Acts). The law placed tighter administrative controls on coastal shipping. More important, it provided that violations of the Sugar Act would be prosecuted in the vice-admiralty courts, in which cases were heard by British-appointed judges with no local juries. Another innovation was the Quartering Act of 1765, which obliged the colonial assemblies to provide housing and supplies for British troops. In addition, well-publicized discussions were taking place in London about taxing the colonies for the support of British troops in Canada and in frontier outposts. Reform of the empire was clearly underway. [source: http://www.alomani.com/knowledge/history/us/sugar_acts.html]