any of the ports of the plantations of Virginia, Bermuda, Barbados, and
other places of America, shall suffer any ship or vessel to lade any
goods of the growth of the plantations and carry them to foreign ports
except in English bottoms," under forfeiture of certain exemptions from
customs.[F] It was followed up four years later (1650) under the
Commonwealth, by an act prohibiting "all foreign vessels whatever from
lading with the plantations of America without having obtained a
license."[G]

Cromwell's code, of which the act of 1381 was the germ, was established
the next year, 1651. Its primary object was to check the maritime
supremacy of Holland, then attaining dominance of the sea; and to strike
a decisive blow at her naval power. The ultimate aim was to secure to
England the whole carrying trade of the world, Europe only excepted.[H]
These were its chief provisions: that no goods or commodities whatever
of the growth, production, or manufacture of Asia, Africa, or America
should be imported either into England or Ireland, or any of the
plantations, except in English-built ships, owned by English subjects,
navigated by English masters, and of which three-fourths of the crew
were Englishmen; or in such ships as were the real property of the
people of the country or place in which the goods were produced, or from
which they could only be, or most usually were, exported.[I] This last
clause was the blow direct to Holland, for the Dutch had little native
products to export, and their ships were mainly employed in carrying the
produce of other countries to all foreign markets. It was answered with
war, the fierce naval war of 1652-1654, in which was exhibited that
famous spectacle of the at first victorious Dutch admiral, Van Tromp,
sweeping the English Channel with a broom at his masthead.

With the final defeat of the Dutch after hard fighting on both sides,