LIST 30 | 10 Oldest Still-Classified Documents at the National Archives |
As of the beginning of 2004, these are the oldest classified documents in possession of the National Archives and Records Administration. If you're wondering how 85-year-old information on naval mines and German invisible ink can still represent such a threat to the republic that it must remain top-secret, you're not alone.
1
memo: Heingelman to Marlenck (October 30, 1917)
2
report: “Detection of Secret Ink” (January 1, 1918)
3
pamphlet on invisible photography and writing, synthetic ink, and other topics (January 1, 1918)
4
“US Naval Mines, Mine Anchor, Mark VI” (January 26, 1918)
5
report: “Secret Inks” (March 16, 1918)
6
“US Naval Mines, Mine Anchor, Mark VI” (May 1, 1918)
7
Ordnance Pamphlet 575: “Enemy Mines” (June 1, 1918)
8 9
report: “German Secret Ink Formula” (June 14, 1918) (one-page and three-page versions)
10
Ordnance Pamphlet 643: “Mine Mark VI and Mods., Description and Operation” (January 1, 1938)
Thanks to Michael Ravnitzky