While there was an active demand for negroes, there was, nevertheless, almost from the first, strong opposition to importing them. This is evident from the fact that during the colonial period the Assembly of Pennsylvania passed a long series of acts imposing restrictions upon the traffic. In 1700 a maximum duty of twenty shillings was imposed on each negro imported. Five years later this duty was doubled.[10] By that time there had arisen a strong adverse sentiment, due partly to economic causes, since the white workmen complained that their wages were lowered by negro competition, and partly to fear aroused by an insurrection of slaves in New York.[11] Accordingly in 1712 the Assembly very boldly passed an act to prevent importation, seeking to accomplish this purpose by making the duty twenty pounds a head. The law was immediately repealed in England, the Crown not being disposed to tolerate such independent action, nor willing to allow interference with the African Company's trade.[12] Either the local feeling was too strong, or the requirements were less, since in spite of this failure there was for a while a falling off in the number imported.[13] A more moderate duty of five pounds was imposed in 1715, but again the English authorities interposed, repealing it in 1719. Meanwhile an act to continue this duty had been passed in 1717-1718, but apparently it was not submitted to the Crown. In 1720-1721 the five pound duty was again imposed, this act also not being submitted. In 1722 the duty was repeated, and once more the law expired by limitation before it was sent up for approval.[14] Up to this time restrictive legislation had been largely frustrated. It had encountered not only the disapproval of certain classes in Pennsylvania, but the powerful opposition of the African Company, which could count on the decisive interposition of the Lords of Trade.[15] The Assembly accordingly submitted the acts long after they had been passed, and made new laws before the old ones had been disallowed.[16] Nevertheless the number of blacks in the colony had steadily increased, and in 1721 was estimated to be somewhere between twenty-five hundred and five thousand.[17] The wrath of the white laborers was correspondingly increased, and in this year they presented to the Assembly a petition asking for a law to prevent the hiring of blacks. The Assembly resolved that such a law would be injurious to the public and unjust to those who owned negroes and hired them out, but the restrictions on importing them were maintained.[18] In 1725-1726 the five pound duty was imposed again, and in the same year five pounds extra was placed upon every convict negro brought into the colony. This became law by lapse of time.[19]