I've re-uploaded some U.S. Army Reference Data publications from the U.S. Army Heritage and Education Center. I've optimized the PDFs (the originals were 100-300MB+) and labelled them a little better so hopefully they're more searchable than on the USAHEC site. These are primary source documents.
These are extremely detailed Tables of Organization and Equipment, but sometimes include other things like logistical data, missions, capabilities and other info. They often include every subunit in a division down to the personnel level, as well as visuals like vehicle graphics and ORBAT charts.
"Reference Data: Armored Infantry Battalion and Medium Tank Battalion" (January 1950)
"Reference Data: Infantry Regiment" (May 1951)
Includes the whole Infantry Division from the triangular era.
"Reference Data for Armored Units" (July 1953)
Includes Armored Division and non-divisional Tank & Cavalry units
"Reference Data: Infantry Regiment" (July 1954)
Includes the whole Infantry Division from the triangular era.
"Reference Data for Armored Units" (March 1956)
Include Armored Division, non-divisional Armored Cavalry Regiment, and Infantry/Airborne Division armored units.
"Reference Data for Armor Units (ROCAD-ROCID)" (May 1957)
Includes Pentomic era Armored Division and Infantry Division armor and cavalry units.
