At the opening of the war of the Revolution, the Narragansett country of Rhode Island, the Southern part of Long Island, New York City and the counties on the Hudson, and East New Jersey had in their population about as large a proportion of slaves as Missouri four years ago. In all the Colonies collectively the black men were to the white men as five to twenty-one. The British authorities unanimously held that the master lost his claim to his slave by the act of rebellion. In Virginia a system of emancipation was inaugurated; and the emancipation of slaves by success in arms Jefferson pronounced to be right. But the system of emancipation took no large proportions: partly because the invaders in the beginning of the war were driven from the Chesapeake; partly because the large slaveholders of South Carolina, on the subjugation of the low country in that State, renewed their allegiance to the Crown; and partly because British officers chose to ship slaves of rebels to the markets of the West Indies. Yet the continued occupation of Rhode Island, Long Island, and New York City, and the exodus of slaves with other refugees at the time of peace, facilitated the movements in Rhode Island and New York for the abrogation of slavery. At the end of the war the proportion of free people to slaves was greatly increased; and, whatever wilful blindness may assert, the free black had the privileges of a citizen.
Here, then, was an opening for relieving the body politic from the great anomaly of bondage in the midst of freedom. But though divine justice never slumbers, the opportunity was but partially seized. The diminution of the number of laborers at the South revived the importation of slaves. The first Congress had agreed not to tolerate that traffic; the Confederacy left its encouragement or prohibition to the pleasure of each State; and the Constitution continued that liberty for twenty years. At the same time slavery was excluded from the whole of the territory of the United States. The vote of New Jersey only was wanting to have sustained the proposition of Jefferson, by which it would have been excluded not only from all the territory then in their possession, but from all that they might gain.