This book is the first of three to examine the genesis, organization and operational deployment of the US airborne divisions in World War II. This volume discusses pre-war and early-war airborne units, detailing how the first ones were formed and the tactical reasons for this. Task organization for combat and details of attached units are also dealt with, together with the unit's command relationship with higher headquarters. The units discussed include the 82d Airborne Division, 1st Special Service Force, 1st Airborne Task Force (1ATF), 509th Parachute Infantry Battalion, 325th Glider Infantry Regiment, 504th Parachute Infantry Regiment, 517th Parachute Infantry Regiment, 1st Battalion, 551st Parachute Infantry Regiment, and the 550th Airborne Infantry Battalion.