The CIA's Declassified UFO Files Are Now Available Online

Project Blue Book was a systematic study of unidentified flying objects conducted by the United States Air Force. It started in 1952. A termination order was given for the study in December 1969, and all activity under its auspices ceased in January 1970.
Project Blue Book is now fully declassified and available to read online. Read all of its 140,000 pages on UFO enthusiast John Greenewald's website The Black Vault.