Unit Serial Numbers from the "First U.S. Army Build-Up Priority Tables, List A, D+1 through D+14" D-Day (Normandy) - Top Secret - BIGOT NEPTUNE

This book presents newly found information concerning the top secret codes assigned to over 2,000 of the World War II US Army troop units chosen to participate in the first stage of the Operation known as D-Day, the Allied Invasion of Normandy, France, on June 6, 1944.

On that day, Allied Forces crossed the English Channel to invade Nazi-occupied Europe, and bring World War II to a close. In the years preceding this operation, Allied planners selected troop units to participate in it, determined their priority of participation, and devised coding systems to keep Invasion preparations and movements confidential.

By late Winter and Spring just preceding the Invasion, these efforts were reduced to top-secret writings entitled "Build-Up Priority Tables", which listed the thousands of US Army units chosen as participating forces. While these "Tables" underwent continuing revision in the months leading up to the Invasion, their earliest versions were formatted in two parts: List "A", specifying participants in an initial 14-day phase of the action, and List "B", designating those for a second phase, days 15 through 90. To ensure secrecy of troop identity and movements, Invasion planners assigned a 5-digit identification code to each unit listed: a "Unit Serial Number". A three-stripe colored bar code was associated with each  serial number, and both numbers and bars were applied to all significant unit and personnel equipment of the invading forces.

In the decades following World War II, much specific information concerning the genesis and assignment of these D-Day Normandy markings were lost to living memory.  This book is an attempt to reconstruct and revive information concerning their creation, usage, and appearance. We have included as well, a listing of over 2,000 specific troop units and their assigned "Unit Serial Numbers", as they appear on an early version of List "A".  The bar codes associated with each listed unit are also shown, in color.