These repeated acts nearly stopped the trade, and the manumission or sale of Negroes by the Friends decreased the number of slaves in the province.  The rising spirit of independence enabled the colony, in 1773, to restore the prohibitive duty of L20 and make it perpetual.[37] After the Revolution unpaid duties on slaves were collected and the slaves registered,[38] and in 1780 an “Act for the gradual Abolition of Slavery” was passed.[39] As there were probably at no time before the war more than 11,000 slaves in Pennsylvania,[40] the task thus accomplished was not so formidable as in many other States.  As it was, participation in the slave-trade outside the colony was not prohibited until 1788.[41]

It seems probable that in the original Swedish settlements along the Delaware slavery was prohibited.[42] This measure had, however, little practical effect; for as soon as the Dutch got control the slave-trade was opened, although, as it appears, to no large extent.  After the fall of the Dutch Delaware came into English hands.  Not until 1775 do we find any legislation on the slave-trade.  In that year the colony attempted to prohibit the importation of slaves, but the governor vetoed the bill.[43] Finally, in 1776 by the Constitution, and in 1787 by law, importation and exportation were both prohibited.[44]

14. Restrictions in New Jersey.[45] Although the freeholders of West New Jersey declared, in 1676, that “all and every Person and Persons Inhabiting the said Province, shall, as far as in us lies, be free from Oppression and Slavery,"[46] yet Negro slaves are early found in the colony.[47] The first restrictive measure was passed, after considerable friction between the Council and the House, in 1713; it laid a duty of L10, currency.[48] Governor Hunter explained to the Board of Trade that the bill was “calculated to Encourage the Importation of white Servants for the better Peopeling that Country."[49] How long this act continued does not appear; probably, not long.  No further legislation was enacted until 1762 or 1763, when a prohibitive duty was laid on account of “the inconvenience the Province is exposed to in lying open to the free importation of Negros, when the Provinces on each side have laid duties on them."[50] The Board of Trade declared that while they did not object to “the Policy of imposing a reasonable duty,” they could not assent to this, and the act was disallowed.[51] The Act of 1769 evaded the technical objection of the Board of Trade, and laid a duty of L15 on the first purchasers of Negroes, because, as the act declared, “Duties on the Importation of Negroes in several of the neighbouring Colonies hath, on Experience, been found beneficial in the Introduction of sober, industrious Foreigners."[52] In 1774 a bill which, according to the report of the Council to Governor Morris, “plainly intended an entire Prohibition of all Slaves being imported from foreign Parts,” was thrown out by the Council.[53] Importation was finally prohibited in 1786.[54]