Intercolonial trafficking is the book subject; the scale, reasons, trader strategies, importance to imperial rivalries, connections to broader commerce and final passages for African slaves. O'Malley says he's concerned with "the regular and visible exchange of enslaved people as property in the markets of early America offered one important site where colonists learned to see African men and women as economic units with their humanity obscured." I enjoyed this book a lot. It's a macro-view book, which normally is not my favorite but the topic was fascinating. There were footnotes throughout which is always a historians favorite thing!

O'Malley has a five prong argument: (1) the intercolonial slave trade was robust in scale, (2) the extensive scale of intercolonial slave trading powerfully shaped enslaved people's experiences, (3) the intercolonial trade was not incidental but vital to the growth British Atlantic slave trade and the growth of American slavery, (4) the economic significance of this commerce extended beyond the profits of selling persons for a higher price, and (5) intercolonial slave influenced imperial policy, pushing the big empires away from mercantilism and towards freer trade.

Even though O'Malley takes a macro-view of the British intercolonial slave trade, he manages to fit poignant stories into each of his chapters that bring his arguments to life. He concludes with what separates the slave trade from other trades.