Project Blue Book was the US Air Force project to study UFO reports and try to make sense of them and determine if there was any sort of threat to the security of the US. In 1969 the project wrapped up with a “nope” and a shrug, but nevertheless kept a whole bunch of stuff classified. A lot of researchers have been driven to distraction by the classified status of the documentation and have spent years making FOIA requests. The National Archives has made a whole lot of these documents available on microfilm, but one feller went ahead and scanned them and has made them available as 130,000 pages of searchable PDFs.
The files are supposedly available on the website “The Black Vault,” but right now all I’m getting is a “this page cannot be loaded” message. I’d bet good money that the site simply got swamped with an exceedingly large number of people who want to download the docs. Or, you know, reptillian overlords. Whichever.