Though his work is not exclusively related to the role of religion in early American history, Holifield's book delivers a detailed explanation of the evolution of the American ministry, which he claims has its origins in colonial America. Holifield's assessment of early American religion follows the traditional scholarship of early American historiography, but does add a unique dimension in his ability to show how the American clergy is specifically unique to the American course of history, and how it has evolved over time. As James Lewis states in his review in the American Historical Review:
Recent American religious historians have focused less on the clergy and more on the people they lead. But leaders matter, and we now have in E. Brooks Holifield's work the first general history of the clergy in America, a rich and complex book on an important and complex subjectIn the end, it is these three distinctions (ordination, call and education) that make Holifield's work a unique addition to early American religious historiography. He demonstrates how over time, ordination and call have dissolved into lesser roles for clerical authority, while education has become the primary source in modern American religion. This in significant because it demonstrates how religion (particularly the clergy) have evolved since the conception of this nation.
Amid the complexity, Holifield identifies authority as his central organizing concept, noting that "the history of any profession must be, at least in part, a story about authority, or the legitimate use of power." Citing Max Weber, he distinguishes three forms of authority based on ordination, call, and education.
Hoilifield's American Ambassadors is a must-read for anyone interested in the evolution of American religion, particularly from the perspective of the American clergy.