 This was followed by the entrance of the United States in the World War, and Major Cattell was ordered to report for duty at Camp Lee, Virginia, on January 5, 1918.Early in the summer of 1918, he was transferred from the Training Camp to the Office of the Chief of Engineers, at Washington, D. C., to organize the Section of Historical and Statistical Data.Under his able guidance the Section collected and put into permanent form all historical and statistical information concerning every unit of engineers, from the date its organization was first proposed in the memoranda of General Pershing or the General Staff, through its authorization, mobilization, training, and shipment overseas, to the date on which it was finally mustered out.