The Army Publishing Directorate (APD) provides links to current Army publications. Some publications require a CAC card login to view them. The Central Army Registry (C.A.R.) also provides links to current Army publications. Some publications require a CAC card login to view them. To find out if an Army publication is current, use the APD Publications/Forms Records Search
Obsolete Digitized Publications
List and Index of War Department Publications-1945 edition of the FM 21-6
Library of Congress- inventory of obsolete technical manuals
DTIC's Technical Reports Search- The Defense Technical Information Center (DTIC) has some current and obsolete Army and Joint publications. The search is clunky at best. Good luck.
Manuals for Courts-Marshal: Library of Congress - Covers 1890- current
Obsolete Military manuals Collection: ISCARL- A collection of field manuals and military documents from the ISCARL Digital Library, including field service regulations.
Pentagon Library: ARs- You can find digitized ARs in the Pentagon Library’s catalog from their browse search by typing in AR. This will list the ARs numerically.
U.S. Army Field Manuals- World War II (Some available in pdf or html format)
World War II Technical Manuals: ISCARL- Collection of 48 WWII Technical Manuals and 2 TMEs (Technical Manual Enemy) available in pdf format.
Joint Publications
Current Joint publications are available from the Joint Electronic Library (JEL). The menu on the left side of the JEL page provides links to Joint Publications, CJCS Directives, Instructions, Manuals, and other joint publications.
Interagency and Sister Service Publications
Marine Corps Publications Electronic Library
National Guard Bureau Publications and Forms
Air Force e-publishing Website (some current Air Force Publications are available