prior to 1763, it had a significant economic impact since 85% of New England rum exports were manufactured from imported molasses. These measures were followed by the Sugar Act and Stamp Act, which imposed additional taxes on the colonies to pay for defending the western frontier. In July 1765, the Whigs formed the First Rockingham ministry, which repealed the Stamp Act and reduced tax on foreign molasses to help the New England economy, but re-asserted Parliamentary authority in the Declaratory Act. However, this did little to end the discontent; in 1768, a riot started in Boston when the authorities seized the sloop Liberty on suspicion of smuggling. Tensions escalated further in March 1770 when British troops fired on rock-throwing civilians, killing five in what became known as the Boston Massacre. The Massacre coincided with the partial repeal of the Townshend Acts by the Tory-based North Ministry, which came to power in January 1770 and remained in office until 1781. North insisted on retaining duty on tea to enshrine Parliament's right to tax the colonies; the amount was minor, but ignored the fact it was that very principle Americans found objectionable. Tensions escalated following the destruction of a customs vessel in the June 1772 Gaspee Affair, then came to a head in 1773. A banking crisis led to the near-collapse of the East India Company, which dominated the British economy; to support it, Parliament passed the Tea Act, giving it a trading monopoly in the Thirteen Colonies. Since most American tea was smuggled by the Dutch, the Act was opposed by those who managed the illegal trade, while being seen as yet another attempt to impose the principle of taxation by Parliament. In December 1773, a group called the Sons of Liberty disguised as Mohawk natives dumped 342 crates of tea into Boston Harbor, an event later known as the Boston Tea Party. Parliament responded by passing the so-called Intolerable Acts, aimed specifically at Massachusetts, although many colonists and members of the Whig opposition considered them a threat to liberty in general. This led to increased sympathy for the Patriot cause locally, as well as in Parliament and the London press. Break with the British Crown Over the course of the 18th century, the elected lower houses in the colonial legislatures gradually wrested power from their Royal Governors. Dominated by smaller landowners and merchants, these Assemblies now established ad hoc provincial