This is a list of historical formations of the United States Army. Units still in existence are in bold.
For specific eras:
Army groups
Field armies
Army corps
Airborne, armored, and infantry are grouped separately. The numbering system for the airborne corps is a continuation of the infantry numbering system.
Airborne corps
Armored corps
Army corps
Army divisions
Air assault divisions
Airborne divisions
Armored divisions
Cavalry divisions
Infantry divisions
Light divisions
Mountain divisions
Reserve training divisions
References
Further reading