1917: AEF Radio Intelligence Section opened intercept site at Souilly, France.
On November 12, 1917, a station in Souilly opened with one sergeant and eight men from the Second Field Signal Battalion. In the first month of continuous 24-hour operation, the station recorded a total of 393 messages and 1,173 calls which were turned over to the RIS for training purposes. From that point on, it became standard for all new intercept operators to first receive training at the schools at Langres and Gondrecourt and then be placed as close to the front line as practicable for their advanced training.
The two operators at the intercept station at General Headquarters recorded and turned over to the RIS, General Staff, an average of 15 messages and seven press reports a day during the month of November 1917. From the date the first intercept was received, messages came in so fast that the tiny staff of the RIS, General Staff, were unable to handle them all, and it soon became necessary to enlarge the section. Officers and clerks were therefore obtained from all available sources. In the case of officers, a search was made for men of high mental caliber who also knew German.