The Mitchell Institute for Airpower Studies have published an extensive analysis on the history of UAVs in the US armed forces. The author of the report is Dr. Thomas P. Ehrhard and the 88 page document covers in detail a very wide spectrum, from the first efforts in the late '50s until the recent UCAV concepts.---



You can download the full document from here: Air Force UAVs: The Secret History (pdf)

More documents published from the Mitchell Institute: Mitchell Institute Publications

Biography of Dr. Thomas P. Ehrhard : http://www.af.mil/information/bios/bio.asp?bioID=12934

Photos:
top - Lockheed Martin D-21 drones carried by a B-52H
mid left - Teledyne Ryan’s Compass Cope (YQM-98A)
mid right - Teledyne Ryan Model 147 (USAF AQM-34)
below - DC-130 Hercules drone control aircraft with BQM-34S Firebee target drones



(via Ares Blog)