African slavery is so much the outstanding feature of the South, in the unthinking view of it, that people often forget there had been slaves in all the old colonies. Slaves were auctioned openly in the Market House of Philadelphia; in the shadow of Congregational churches in Rhode Island; in Boston taverns and warehouses; and weekly, sometimes daily, in Merchant's Coffee House of New York. Such Northern heroes of the American Revolution as John Hancock and Benjamin Franklin bought, sold, and owned black people. The family of Abraham Lincoln himself, when it lived in Pennsylvania in colonial times, owned slaves.[1]...