Both the US and UK governments attempted desperate measures during World War I in an effort to maintain wartime production levels of necessary commodities and to allow for their economical purchase by the military. Loft (1986a, 1986b, 1990) has studied the British experience in depth, concluding that UK cost accountancy 'came into the light' as a result. It might be expected that similar developments would have occurred in America with the activities of the War Industries Board. In both countries, national associations were established in the immediate aftermath of the war to promote the professional standing of cost accountants. This paper utilizes archival materials in an effort to investigate whether US cost accountancy was developing more sophisticated costing techniques as Loft has claimed for the UK, or whether practitioners in this country were left 'still cursing the darkness'. Our findings suggest that cost accountancy developed in parallel fashion in both countries. US and UK cost accounting professionalism was dominated by the presence of leading financial accounting practitioners, and in both countries the movement towards more sophisticated costing techniques was gradual rather than dramatic.