According to an Air Force press release, a reenactment of the first flight of a US military airplane will occur at Fort Sam Houston in Texas, commemorating the flight 100 years ago today.

The celebration is reportedly being held by both the Army and the Air Force.  Obviously, the first military flight was conducted in a US Army aircraft.

Update: Read the post-celebration article, which includes pictures of the unique flyby of the Wright B Flyer.