In the 1860s mass emigration from Merthyr Tydfil made a major impact on the town's fortunes and developing public sphere. The ‘extraordinary drain’ occasioned much concern and comment and reconfigured ongoing debates about Merthyr's contemporary condition and future survival. In turn, local power struggles, notions of the town's interests and emerging civic consciousness influenced interpretations of the nature, causes and meanings of the outflow. Emigration and the ‘urban’ thus interacted tellingly to help shape contemporary mentalities.