Between 1780 and 1918, over one million petitions from across the four nations were sent to the House of Commons. A Nation of Petitioners is the first study of this nineteenth-century heyday of petitioning in the United Kingdom. It explores how ordinary men and women engaged with politics in an era of democratisation, but not democracy, and restores their voices and actions to the story of UK political culture. Drawing on more than a million petitions, as well as archives of leading politicians, institutions, and pressure groups, Henry J. Miller demonstrates the centrality of petitions and petitioning to mass campaigning, representation, collective action, and forging collective identities at the local and national level. From the early nineteenth century, the massive growth of petitions underpinned and reshaped the popular authority of the UK state, including Parliament, the monarchy, and government. Challenging accounts that have stressed disciplinary or exclusionary processes in the evolution of popular politics, A Nation of Petitioners conclusively establishes the importance of the mass participation of ordinary people through petitions.