Following the Second World War, the United States would become the leading 'neoliberal' proponent of international trade liberalization. Yet for nearly a century before, American foreign trade policy was dominated by extreme economic nationalism. What brought about this pronounced ideological, political, and economic about face? How did it affect Anglo-American imperialism? What were the repercussions for the global capitalist order? In answering these questions, The 'Conspiracy' of Free Trade offers the first detailed account of the controversial Anglo-American struggle over empire and economic globalization in the mid- to late-nineteenth century. The book reinterprets Anglo-American imperialism through the global interplay between Victorian free-trade cosmopolitanism and economic nationalism, uncovering how imperial expansion and economic integration were mired in political and ideological conflict. Beginning in the 1840s, this conspiratorial struggle over political economy would rip apart the Republican Party, reshape the Democratic Party, and redirect Anglo-American imperial expansion for decades to come.