The expansion of the Seamen Acts into North Carolina and Georgia occurred simultaneously with the political ascension of Jacksonian Democrats in the United States and the Whigs in Great Britain. While these two groups shared a penchant for political reform, they diverged on the issue of slavery and black citizenship. The continued arrests of free black sailors forced diplomats from both nations to consider their diverging trajectory. The primary argument of the chapter is that the diplomatic jousting of Britain – on behalf of the citizenship rights of its black maritime workforce – led Democratic Party jurists to craft vital constitutional ideologies that would in time become central to antebellum constitutionalism. Five years before New York v. Milne and twenty-five years before Dred Scott, the Cabinet members in the Jackson administration endorsed a powerful version of state policing authority and refuted the possibility of black citizenship. These ideas were crafted in response to the Seamen Acts.