Link to full series here.
This is the last episode of the series, but there are more Crash Courses on subjects from literature to chemistry here:
If you're as old as I am, you remember classroom films and filmstrips (a series of projected stills accompanied by recorded narration, for you young whippersnappers) that were nowhere remotely as interesting as these. Bravo to the producers.
Finally, as a bonus, here are some outtakes: