The Majestic 12 (MJ-12) Papers
A set of documents that arrived on a filmmaker's doorstep as undeveloped 35mm negatives, describing a secret committee of scientists and officials convened by President Truman in 1947 to manage the recovery of a crashed craft and its occupants near Roswell, New Mexico.
Why it was classified
By their own markings, TOP SECRET / MAJIC — EYES ONLY. In practice the Air Force's Office of Special Investigations concluded the briefing memo was fabricated, and the FBI stamped its own copy 'BOGUS' after checking the formatting and signature block against genuine Truman-era documents.
Why it matters
The government investigated a UFO document and published the finding that it was a forgery — and the papers only grew more influential. MJ-12 remains the load-bearing wall of American cover-up lore, held up by a file that debunks it.