Within the expanding but unstable environment of industrial America, Philadelphia machine builders assumed a leadership position that only ended with the arrival of more dynamic centres of production at the end of the nineteenth century. Exploiting local cost advantages and organised into large-scale units of production, workshops forged reputations as builders of heavy machinery. The development of Philadelphia engineering is, clearly, not explained by the bureaucratic, mass production, deskilling, corporate model of industrial development advanced by Alfred D. Chandler. Approaching proprietors sociologically, while it can never avoid historical judgement, at least sidesteps the loaded and abstracted morality saturating the now discredited 'industrial statesmen' versus 'Robber Baron' debate. While most historians are open to the argument that the Civil War was a battle for liberal capitalist values, most are sceptical of the claim that industrial capital was a revolutionary agent in this transformation.