This law was for a time enforced,[30] but by the beginning of the eighteenth century it had either been repealed or become a dead letter; for the Act of 1708 recognized perpetual slavery, and laid an impost of L3 on Negroes imported.[31] This duty was really a tax on the transport trade, and produced a steady income for twenty years.[32] From the year 1700 on, the citizens of this State engaged more and more in the carrying trade, until Rhode Island became the greatest slave-trader in America. Although she did not import many slaves for her own use, she became the clearing-house for the trade of other colonies. Governor Cranston, as early as 1708, reported that between 1698 and 1708 one hundred and three vessels were built in the State, all of which were trading to the West Indies and the Southern colonies.[33] They took out lumber and brought back molasses, in most cases making a slave voyage in between. From this, the trade grew. Samuel Hopkins, about 1770, was shocked at the state of the trade: more than thirty distilleries were running in the colony, and one hundred and fifty vessels were in the slave-trade.[34] "Rhode Island," said he, "has been more deeply interested in the slave-trade, and has enslaved more Africans than any other colony in New England." Later, in 1787, he wrote: "The inhabitants of Rhode Island, especially those of Newport, have had by far the greater share in this traffic, of all these United States. This trade in human species has been the first wheel of commerce in Newport, on which every other movement in business has chiefly depended. That town has been built up, and flourished in times past, at the expense of the blood, the liberty, and happiness of the poor Africans; and the inhabitants have lived on this, and by it have gotten most of their wealth and riches."[35] The Act of 1708 was poorly enforced. The "good intentions" of its framers "were wholly frustrated" by the clandestine "hiding and conveying said negroes out of the town [Newport] into the country, where they lie concealed."[36] The act was accordingly strengthened by the Acts of 1712 and 1715, and made to apply to importations by land as well as by sea.[37] The Act of 1715, however, favored the trade by admitting African Negroes free of duty. The chaotic state of Rhode Island did not allow England often to review her legislation; but as soon as the Act of 1712 came to notice it was disallowed, and accordingly repealed in 1732.[38] Whether the Act of 1715 remained, or whether any other duty act was passed, is not clear.