Here is a short film from 1941 by Warner Bros titled “The Tanks are Coming.”  The film is part comedy, part propaganda and frankly the humor is more than a bit dated.  However, the film includes a good deal of interesting footage of early war US M2 light and M2 medium tanks.  There are some good training shots as well, featuring driving and gunnery simulators.  The film was shot on location at Fort Knox.