The Story of Jazz Guitar, on All About Jazz

Short but good, with some excellent videos embedded. Here's the ToC with links:

1. The Beginnings: Blind Lemon Jefferson
2. Eddie Lang / Eddie Durham / Lonnie Johnson
3. Django Reinhardt / Charlie Christian / Tiny Grimes
4. Herb Ellis / Barney Kessel / Charlie Byrd
5. Wes Montgomery / Kenny Burrell / Joe Pass / Jim Hall
6. George Benson
7. John McLaughlin / John Scofield / Mike Stern