The lynchpin of Caroline economic reform was the Reglamento de comercio libre of 1778 which, by providing for greater freedom for trade within the empire, offered the prospect of unlocking the economic potential of the Hispanic world. The main provisions of the Reglamento may be briefly stated. First, and most important, it released colonial trade from the constraints of the old commercial system, pivoted on Cádiz and dominated by a privileged oligarchy of Andalusian merchants. In 1778, the Cádiz monopoly was formally ended and henceforth all the major Spanish and Spanish American ports were open to trade with each other. To promote colonial commerce, the Reglamento also reduced the many restraints that affected transatlantic shipping and trade. Thus the formalities required to ship cargoes to the Americas were relaxed, several traditional impositions on shipping and trade were abolished, and duties on trade were both standardized and reduced. Steps to enlarge the scale of Spain's trade with its colonies were, moreover, matched by measures to promote trade in Spanish products, so as to stimulate growth and development in metropolitan agriculture and industry. To this end, differential tariffs were placed on exports from Spain to its colonies, forcing foreign products to pay heavier duties than goods made in Spain.