This case study of late-nineteenth century federal courts in the United States sheds light on two seemingly unrelated questions of general interest to political scientists: What tools are available to party leaders who seek to institutionalize their policy agendas or insulate those agendas from electoral politics? and How do we account for expansions of judicial power? Using an historical–interpretive analysis of partisan agendas, party control of national institutions, congressional initiatives relating to federal courts, the appointment of federal judges, judicial decision making, and litigation patterns, I demonstrate that the increased power, jurisdiction, and conservatism of federal courts during this period was a by-product of Republican Party efforts to promote and entrench a policy of economic nationalism during a time when that agenda was vulnerable to electoral politics. In addition to offering an innovative interpretation of these developments, I discuss the implications arising from this case study for our standard accounts of partisan politics, political development, and the determinants of judicial decision making.