Margaret Ellen Newall's ambitious survey of the economic and legal development of Indian slavery and servitude in New England argues that although the region's labor regime differed from other English colonies, it “looks less exceptional than previous scholarship has suggested” (p. 6). Before 1700 Indians rather than Africans were the dominant form of nonwhite labor, and Indians continued to be enslaved or endure service for life for more than two centuries. As in other New World colonies that embraced slave labor, New England leaders made a conscious decision to exploit Indian and subsequently African slaves in ways they did not treat European servants, and those who acquired captive Indians were also among the first to purchase Africans. Enslaving Native Americans proved a cheap solution to labor shortages, since bound workers were acquired within the region through capture or legal processes, so they cost only 10 to 25 percent of the price of imported Africans. Local elites held most of the Indian slaves, ensuring that legislatures and courts would serve slaveholders' interests. Some English officials did look askance at Indian slavery, considering Native Americans subjects of the crown on an equal plane with colonists (hence brethren by nature), but during the formative seventeenth century they lacked power to prevent colonists from asserting sovereignty over Indians in the region.

Acquiring captives became a primary purpose of English conflicts with Native Americans, beginning with the Pequot War of 1637 which established policies that continued through King Phillip's War of 1675–1676, and the northeastern Wabanaki conflicts of 1676–1749. In each, colonial soldiers were recruited and paid with promises of plunder including captives. Massachusetts became the first English colony to legalize slavery in 1641 in response to a need to define the status of captured Pequots. They rationalized captive taking in just wars, and enslavement of “strangers …sold to us” (p. 53), but simultaneously held Indians to be in rebellion. Consequently fighters were denied protections due foreign combatants and noncombatants judged supporters of insurrection, leading to widespread enslavement of women and children. But the legislatures were sufficiently uncomfortable with the idea of Indian slavery that they avoided clear definitions of who was eligible to be enslaved and whether slavery was hereditary. Instead, “local norms and usages, and the ability of purported owners to invoke the policing power of local officials and institutions, shaped what was possible for the owners of captives” (p. 54).

Following King Phillip's War the colonial governments viewed all Indians as subject people with rights of petition, and either outlawed slavery or set limits on the terms of war captives retained within the region (10 years for adults and until age 25 or 26 for children), rendering them servants in law instead of slaves. Nonetheless Indians who entered servitude faced a high risk of remaining slaves for life and their children inheriting that status because they were not expected to return to a separate and autonomous existence but to continue working for the English and to obey English laws. In the early eighteenth century New Englanders briefly turned to importing Indian slaves from the Carolinas, but increasingly found forcible indenturing of Indian children and enslavement for crime or debt safer and more effective strategies for maintaining a supply of bound Native American labor.

Newall discusses the economic role of Indians in household production, production for export, and military service, as well as wage labor in agriculture and maritime pursuits. The incorporation of enslaved Indians into English households led to a hybrid culture, but put extreme pressure on them to adapt to English ways. The many forms of forced servitude contributed to the drastic decline of local Indian populations, economies, and cultures, undermining “fertility rates, mortality, child rearing, kin networks, gender roles, and other aspects of Indian life” (p. 236). Nonetheless, the existence of approximately 3,000 Indians who continued to live in the region as free persons precluded complete identification of Indians with slavery.

In New England, Indian slavery and servitude evolved in tandem with African slavery. From the outset, through trade with other mainland colonies and the Caribbean, New Englanders were intimately connected to and knowledgeable about evolving labor systems elsewhere. They sold about one quarter of war captives outside the colony, not only to Bermuda, Barbados, Providence Island, and Jamaica, but also to Virginia, the Wine islands, and Mediterranean ports, where they were often exchanged for enslaved Africans. As numbers of Africans increased in the early eighteenth century, laws were adopted that regulated the behavior of both African and Indian servants, incorporating them into a “subclass of servants and slaves of color, subject to distinct legislative regimes, antimiscegenation laws, and ‘black codes' of conduct that separated them from English and free Indians,” further undermining Indians' status, and leaving biracial children liable to classification as black and thus hereditary slaves (p. 186). Conflation of the two groups later contributed to historical amnesia about Indian slavery in New England. The legal challenges second- and third-generation and biracial Indian slaves brought to courts in the mid-eighteenth century, however, sparked the beginnings of an abolitionist movement that later included Africans among its constituents. Nonetheless, Indian slavery continued through the 1780s, but numbers declined rapidly as more freedom suits succeeded, and, after 1800, as incarceration replaced judicial enslavement as the preferred punishment for crimes.

Readers may wish Newall had made more effort to quantify the extent of Indian servitude and slavery in the region. She states that enslaved Indians “likely numbered in the thousands” (p. 14), but provides a clear estimate only for the number of captives taken in King Phillip's War (at least 2,000). Unfortunately additional estimates will remain less precise than estimates of numbers of bound laborers for other regions since shipping records are of no help for locally obtained captives, sale records are sporadic or lacking, and the status of many bound laborers established de facto. The size and composition of the slaveholding class, however, could be more precisely delineated. In most discussions Newall asserts that slaveholding was concentrated among elites, but occasionally argues that slave ownership “spread quickly even to the middling ranks of society” (pp. 5, 158, 171). Evidence from probate inventories or tax lists for selected localities might be employed to clarify the extent of slaveownership and hence of the groups with the greatest incentives for supporting slavery.

Overall Brethren by Nature is an important contribution to the economic history of colonial and early national New England. By underscoring the region's connections to the forms of slavery developing elsewhere, and the similar violent means by which all colonial elites addressed chronic labor shortages, it contributes as well to studies of slavery throughout the early modern Atlantic.