During the summer of 1847, hundreds of thousands of Irish migrants fleeing famine and social upheaval in their native land made their way to the bustling North Atlantic port cities of Montreal and Liverpool. Their migration was marked by outbreaks of epidemic disease that helped fuel public doubts about the project of liberal urban governance. The imperial, colonial and municipal authorities were forced to adopt innovative practices of authority in the midst of the ensuing crisis. This article explores the similarities between the response to these events in Montreal and Liverpool as well as the way that these responses were inextricably linked to local circumstances. In doing so, it examines the way that political practices were debated an...