As the effects upon New England, until the following century, were mainly indirect, it is not necessary to give the details of the various acts in the order in which they were passed. Their aim was twofold—destructive and constructive. In the former aspect, they aimed at diminishing, if not wholly destroying, the shipping, and so both the commerce and the naval power of competing states. On their constructive side, their design was to build up the shipping of the English Empire, and, in reference to certain articles, to make England the sole market for their trade. As to the first point, the colonies were put upon the same basis as England herself; and, in exchange for the advantages derived by her from the second, she offered the colonists certain privileges in the home markets. It was, therefore, enacted that no trade could be carried on between England and her dominions except in ships owned by her or them, and manned by English or colonial crews, the same restriction applying to all goods imported into either from any foreign country or colony in America, Asia, and Africa.[754] This was merely an extension of acts already frequently passed, or provisions in the early charters, such as we have already noted. Footnote 754: Macdonald, _Select Charters_, pp. 106 _ff._, 110 _ff._, 133 _ff._ The other main point, that of limiting the markets in certain goods to England, was also merely an extension of another long-familiar idea. When the economic organization, in the later Middle Ages, was still largely municipal, it had been found advantageous to designate certain towns as the sole markets, or “staple,” for certain goods. For some centuries, the belief in the economic soundness of this practice continued to be held; and, as we noted in the very first charter relating to America,—that of Cabot, in 1496,—it was required that all goods should pass through the port of Bristol. The Navigation Act of Charles II required that certain “enumerated” commodities produced in the colonies should be sold only in England, and not directly to foreigners, thus making England the “staple” for the Empire in the same way in which certain municipalities had formerly been the staples for the kingdom. Theoretically, the colonists were in the same relative position to England in the matter as were Englishmen at home to the staple municipalities, although, of course, the practical disadvantages and injustice to the colonists were much greater when the scheme was made imperial.