The Chartist movement was the mass-movement for constitutional reform in mid-nineteenth-century Britain. Chartism is one of the most written about subjects in modern British history, yet the ideas of the movement remain strangely neglected. This thesis tackles this problem by examining Chartist ideas along a broad front. By examining the political thought of a movement, rather than a select number of highly educated intellectuals, this thesis also makes a statement about how to study popular political ideas. Chapter One locates the foundations of Chartist political thought in the movement’s social and cultural context. It asks what the Chartists read and were able to read, how they viewed knowledge and education, and the religious basis of Chartist intellectualism. Chapter Two turns to Chartist political theory, in particular, the Chartist interpretation of the British constitution. It is shown that Chartists drew on a sophisticated conception of the common law that rooted the British Constitution in natural law. Chapter Three considers Chartism’s economic ideas, which, it is argued, must be understood in relation to their understanding of classical political economy. Chapter Four examiners Chartist natural-right arguments alongside the ideas of non-Chartist radicals. Finally, Chapter Five traces the careers of a number of Chartists and the influence of Chartist ideas in America. It also attempts to take account of what Chartism meant to Americans. By considering these topics, this thesis provides a clearer impression of why ideas were important to the Chartists, what sort of ideas the Chartists held, and the legacies of Chartist ideas for democratic politics later in the century.