Degrees of Freedom: Louisiana and Cuba after Slavery, and: Slavery and the Commerce Power: How the Struggle Against the Interstate Slave Trade Led to the Civil War, and: The Problem of Emancipation: The Caribbean Roots of the American Civil War (review)

Atlantic history as a field of study is old and yet immature. Unlike scholarship in women's and African American history, for example, fields that have far transcended early generational forms of "her-story" and "black achievement," Atlantic scholarship has yet to show comparable progress. From the earliest histories—Lowell Ragatz's The Fall of the Planter Class in the British Caribbean, 1763–1833 (1928) and Eric Williams's Capitalism and Slavery (1944) surely qualify—to recent varieties, the principal explanatory mechanism remains largely the same. Now as then, a hero–villain dynamic takes center stage. Self-interest casts as villain. Ideals—particularly the egalitarian ethos—play the hero.

Such considerations assume increasing importance today as the field widens its scope over time and space. In a departure from a traditional focus on colonial empires between 1500 and 1825 and conspicuous neglect of the independent American republic, Atlantic histories now incorporate the United States and extend their storyline into the twentieth century. The expansion of the field's geographical breadth and topics examined are welcome developments, as they broaden perspectives of the early republic and promise true Atlantic study rather than imperial history in another guise. Still, quantitative expansion holds little hope for the field's qualitative progress until scholars venture from timeworn plotlines and explore the more significant possibility that ideals are self-interested.

At first glance, David Lightner's Slavery and the Commerce Power appears anything but Atlantic history. Yet the slave trade, more than slavery, is Lightner's focus, and he combines the two subjects in ways certain to engage Atlantic scholars. At the heart of his book is the issue of whether the American federal government possessed regulatory power over the domestic slave trade, and, if so, why such authority remained dormant, unlike the federal government's assertion of the commerce power to prohibit the trans-Atlantic trade after 1808. Lightner shows the Constitutional Convention did not address the domestic trade. Still in its relative infancy, that trade had yet to assume the lucrative importance it would after the trans-Atlantic prohibition limited the South's slave market to domestic sources of supply.

Lightner excels too in demonstrating that American abolitionists recognized that the failure to protect the domestic slave trade offered them an opportunity to attack "the great jugular vein of slavery" and they mobilized politically to do so—only to encounter insuperable opposition by the U.S. Supreme Court (102). As slave prices skyrocketed by 1830, American jurisprudence, dominated by slaveholders, blocked the abolitionists' goals. Whereas the Marshall Court had avoided pinpointing federal–state jurisdictional boundaries in Gibbons v. Ogden (1824), the Taney Court provided crystal-clear delineation in Dred Scott v. Sanford (1857) by asserting that state-protected property rights extended beyond the reach of the federal commerce power. Accordingly, Lightner depicts a road to disunion paved with slaveholders' attentiveness to property rights.

Lightner's insightful recounting of American jurisprudence, however, digs little deeper. In grounding his understanding of southern self-interest in the profits of slave sales, he hints only briefly at the domestic trade's far larger value: providing indispensable capital fluidity that underwrote southern slave investments as a whole, equity amounting to two-thirds of the South's immense wealth in 1860, or approximately $80 billion in 2009 dollars. Significantly, many northerners understood—and by 1860 voted against—this basis of southern political...