Ha, I was just about to post the Internet Archive's link to Long Distance and you beat me to it. Even though an AT&T promo, this is a great documentary. It's a

Ha, I was just about to post the Internet Archive's link to Long Distance and you beat me to it. Even though an AT&T promo, this is a great documentary. It's an excellent exposé of the forerunner to AT&T's post-War Long Lines—the cable and wireless systems—which was pretty much state of the art before the Long Lines microwave system superseded it. The doco is particularly useful for historians of tech/communications because it provides an excellent overview of how the US's telephone comms worked by the outbreak of WWII—from the women who ran the network to images of line, terminal and transmitting equipment. It's and excellent snapshot in time. Two notable things are the huge number of women employed to do the manual routing—Strowger switching being essentially limited to towns and crossbar/long distance dialing yet to be deployed—and the methods used to lay underground cables. Women's employment 80 years ago was very different to today and the film illustrates the fact; on the other hand, there's a remarkable resemblance between the drums of cable and cable laying techniques of 1941 and the laying of fiber optic cable of today—those 1941 cable drums could equally have carried fiber. Some things never change. Incidentally, I used to work on microwave television links.