Jörg Ulbert and Lukian Prijac, eds., Consuls et Services Consulaires Au XIXe Siecle = Die Welt Der Konsulate Im 19. Jahrhundert = Consulship in the 19th Century (Hamburg: DOBU, Dokumentation & Buch, 2010).
The volume contains an overview of the US Consular Service that emphasizes reform and professionalization: Christoph Strupp, “Das US-amerikanische Konsularwesen im 19. Jarhundert” (218-33).
The thirty-four other essays in the volume include overviews of several services, as well as more focused studies. A few of the essays are in English; most are in French or German.