Project Jefferson was designed to reproduce a strain of genetically-modified anthrax isolated by Russian scientists during the 1990s. It was disclosed (together with Project Bacchus, Project Clear Vision) in a September 4, 2001 article in The New York Times (see http://www.nytimes.com/2001/09/04/world/us-germ-warfare-research-pushes-treaty-limits.html).
Since the anthrax attacks happened after 9/11 both terror attacks were often connected. But could it be that the anthrax attacks had nothing to do with 9/11? Instead somebody felt threatened by the disclosure of the biological weapons programs by the New York Times and started the anthrax attacks quite independently not because of 9/11, but instead because of 9/4?