Exploring both his life and legacy, the first full biography of William Sharman Crawford, the leading agrarian and democratic radical active in Ulster politics between the early 1830s and the 1850s. This biography places the life and ideas of William Sharman Crawford in the context of the development of radical liberalism in Ulster province over a more extended period, from his father's involvement in the Volunteers in the era of the American and French revolutions, through William's own leadership in Irish and British radical reform movements, including the Repeal Association, Chartism, and the Tenant League. It explores his attempts to reconcile Irish patriotism with the existence of the Union through the concept of "federalism," his efforts to act as an "ideal landlord" in the face of agrarian unrest and famine, and his deep commitment to attaining land and welfare reforms that he believed would empower both tenant farmers and the laboring poor. William Sharman Crawford and Ulster Radicalism traces the legacy of his politics through the political careers of his children James in Gladstonian liberalism and Mabel in the women's suffrage movement, both of whom sought, in common with Presbyterian allies such as James McKnight, to carry his ideas into the later nineteenth century. It concludes with the collapse of the family's radical tradition in the following generation, as his grandson Robert Gordon came to reject liberal unionism and take an active role in the Ulster Unionist movement from the 1890s. Through an assessment of the Sharman Crawford family over four generations, William Sharman Crawford and Ulster Radicalism explores the resilience of the Ulster Protestant radical tradition in the wake of the setbacks of 1798, its strengths and weaknesses, and its relations with Irish Catholic nationalism, British radicalism, the conservative landed, and Orange traditions within Ulster.