In part one of a two-part series, this article paints a statistical picture of the impact World War II had on the Federal Probation System. During World War II, Federal probation officers assisted offenders in securing military service while striving to rehabilitate offenders and protect communities. This article attempts to articulate how the Federal system went about its business under wartime conditions and the impact of their efforts. In order to bolster the ranks of the armed forces, Congress passed the Selective Training and Service Act of 1940, accommodating select ex-offenders under Federal supervision. By June of 1944, there were 6,464 Federal offenders serving in the Army and the Navy with 37 percent, less than 1 percent, dishonorably discharged. Alongside offenders on the battlefields of World War II were Federal probation officers from across the country. By the end of the war, 92 out of a total of 274 Federal probation officers served in this country’s armed forces. The Second World War provided a new type of offender to supervise, military offenders. Part two of this series will describe how the Federal Probation Service dealt with actual correctional concerns confronted during the war. Endnotes, references