Why did whigs consider the Treaty of Utrecht to be an imperial disaster? Contemporary scholarship makes this a difficult question to answer. Imperial historians insist that it was an imperial triumph. While political historians point to rough-and-tumble party politics that was not about empire. This article aims to recover the rich intellectual history of party political debate about empire in the age of Anne. I suggest that there was bitter conflict between tories who sought territorial empire based on South American mines, and whigs who sought a manufacturing empire based on penetrating South American markets with British manufactures. The Sacheverell trial and its aftermath marked a turning point in British imperial policy. As a result the whigs felt betrayed, venting their anger in the immediate aftermath of the Hanoverian succession.