See Wiliam Freehling,
The Road to Disunion: Secessionists at Bay, 1776-1854: Volume I, pp. 131-134 on emancipation in the mid-Atlantic states. The laws typically took the form of declaring that all slaves born after a certain date had to be freed on reaching a certain age. Of course this virtually invited slaveholders to sell young slaves south before they reached that age. New York and New Jersey did indeed enact laws outlawing such conduct, but they were (at least at first) full of loopholes:
"In terms of absolute number of slaves, the someday-to-be-northern Mid-Atlantic region was surprisingly southern at the time slavery was first considered an American problem. In 1790, the state of New York possessed the sixth largest number of slaves, ahead of Kentucky; New Jersey was eighth, ahead of Delaware; Pennsylvania was tenth, ahead of Tennessee. New York, New Jersey, and Pennsylvania, taken together, contained one and a half times more slaves than did Georgia.
"Still, this then-most-northern South already possessed in 1776 the key condition for southern Conditional Termination: a low and declining percentage of blacks.
19 Mid-Atlantic white population grew much faster than the region’s black inhabitants. New York was 14% black in 1756, 12% in 1771, 6% in 1790. This eighteenth-century process in Mid-Atlantic states was a rehearsal for slower nineteenth-century drifts of the Border South towards black percentages under 10%, that magic plateau which in both centuries established the first condition for seriously considering abolition.
"One condition still delayed emancipation in the then-most-northern South. In a nation equating life, liberty, and the pursuit of happiness with life, liberty, and the protection of property, liberty for slaves required payoff to property owners. The problem made post-nati emancipation particularly attractive. If only slaves not yet born were freed, perhaps no payoff would be necessary.
"Mid-Atlantic slaveholders begged to differ. They had paid for the perpetual labor of slaves unborn in the high purchase price of slave “wenches.” State seizure of the afterborn might also be an entering wedge. Reformers might move on to freeing those born before the arbitrary date.
"Such intransigent defense of slave investment might sound too southern to be northern. Northerners supposedly only emancipated because slavery did not pay in colder climes. But Mid-Atlantic states are in the same climatic zone as the Border South, and some northern slaveholders fought for their investment for as many decades as did William Lowndes Yancey. Planters in eastern New Jersey and along New York’s Hudson River, where slaves in some spots comprised as much as 30% of the population, were tolerably pleased with their profits and intolerably outraged that slaves could be seized when each was still worth several hundred dollars. Our strongest opponents, a New York proponent of black freedom later remembered, “were chiefly Dutch. They raved and swore by
dunder and
blixen that we were robbing them of their property.”
20
"New York and New Jersey slaveholders who raved and swore still differed significantly from 1861 secessionists. While all these reactionaries wished to protect a valuable investment, New York and New Jersey slaveholders considered property in labor neither economically indispensable nor racially necessary. Believing a few blacks easy to control, they primarily wished to be paid to be virtuous. Their tactics were not to stand and deliver on some Civil War battlefield but to stall for more years of profits, then to raise the ante for giving up the profitable. The great Yankee battle was not so much over whether the post-nati would be freed but when, at age 21 or 28? Seven years of delay made some difference to capitalists—and enormous difference to bondsmen.
"Emancipation after the American Revolution occurred without slaveholder-enforced delays only in the almost-slaveless, northernmost New England states of Massachusetts, New Hampshire, and Vermont. In more southerly Rhode Island, where 6% of the population was enslaved in 1776, post-nati emancipation was delayed until 1784. Freedom for those born earlier was never passed; 108 slaves remained in Rhode Island in 1810. In Connecticut, where 5% of the population was enslaved in 1790, post-nati emancipation was put off until 1794 and freedom for other slaves not decreed until 1848.
21
"In Pennsylvania, where over 10,000 blacks resided, a powerful Quaker antislavery faction secured the first American post-nati law in 1780. The vote was close, 34–23. The law delayed freedom for the afterborn until age 28, a concession to slaveholders who had called the initial bill, freeing females at 18 and males at 21, a violation of property holders’ liberty. The Pennsylvania legislature never decreed liberation for blacks born before 1780. Over 400 blacks remained enslaved in the Quaker State in 1830.
22
"New Jersey’s slaves, 11,423 in 1790, had to wait longer for legislative relief. In 1804, the legislature freed those born thereafter, males at age 25, females at 21. At slaveholders’ insistence, legislators allowed masters to “abandon” afterborn black children, then be paid by the state to raise (and work) those “abandoned.” These payments comprised over a third of the state’s nonpenal and nonmilitary budget.
"New Jersey repealed the budget-busting abandonment policy in 1811. Slaveholders then could re-enslave those “abandoned,” as if not a cent had been paid. Over 7500 slaves remained in New Jersey in 1820, over 2200 in 1830. Eighteen lifelong black apprentices remained in 1860 to cheer the election of the Great Emancipator, whose war against the Slavepower finally ended slavery in the North.
23
"In New York, slaveholders stalled off post-nati emancipation until 1799. They then secured the right to keep the afterborn until ages 28 (males) and 25 (females). Slaveholders also enjoyed more liberal “abandonment” bounties than New Jersey would later provide. Twenty thousand New York blacks remained enslaved in 1800, 15,000 in 1810, 10,000 in 1820. The institution was not wiped out of the Empire State until 1827.
24
"Thousands of New York and New Jersey post-nati slaves, although supposed to be freed on designated birthdays, remained perpetually enslaved. Post-nati emancipation laws almost invited masters to sell afterborn slave children south, before the emancipating birthday. Both New York and New Jersey early forbade this cynical practice. But both states initially provided too mild penalties to stop the travesty. Both waived penalties if slaves “consented” to transfers. Both allowed state officials to save prison expenses by selling convicted slave “criminals” to Dixie. One historian estimates that twice as many New York slaves were ultimately sold down south as were freed.
25
"These evasions yielded notorious stories and a public outcry. Both states closed post-nati loopholes within two decades of emancipation. Antebellum New Jersey, however, never ceased cashing in black “criminals” at New Orleans slave auctions. And immediately before New Jersey’s crackdown on selling post-nati slave children down south, a Dutchman named Nicholas Van Wickle received permission to cash in his 60 slaves in Louisiana, based on their “consent” to forgo freedom.
26
"Van Wickle’s grotesque culmination serves as climactic symbol of delays and evasions in what became the most southern layer of free states. An end to Yankee slavery at last came, not because slaveholders were going broke but because the huge nonslaveholding majority finally acted to eliminate the institution. The somewhat encouraging lesson of the sadly slow reform was clear. Assuming that low free black concentrations and modest compensations to slaveholders could be achieved, Conditional Terminators could eventually meet other conditions..."
Far from a monolithic block of diehard slave states, the South in the eight decades before the Civil War was, in William Freehling's words, "a world so lushly various as to be a storyteller's dream." It was a world where Deep South cotton planters clashed with South Carolina rice growers, where...
books.google.com
https://books.google.com/books?id=iqdoAgAAQBAJ&pg=PA133
https://books.google.com/books?id=iqdoAgAAQBAJ&pg=PA134
