For more from the AT&T Archives, visit http://techchannel.att.com/archives

This film focuses on the integrity and reliability of the entire Bell System network, circa 1967, to handle large quantities of not just voice information and phone calls, but also data, text via teletype, pictures, and television signals. It's a series of small case studies in how the national system fit together to deliver all kinds of information, from tracking train cars to transmitting live television broadcasts. The narrator steers the viewer from Oklahoma, to Chicago and Cleveland, to the Pacific Northwest, down to Dallas and east to Pittsburgh and New York City. In Tacoma, they peek in on that year's Daffodil Festival. In NYC, it's not specified, but the television program the film visits is actually an episode of the Bell Telephone Hour from 1966, with a young Peter Marshall and an older Ray Bolger performing a song-and-dance number.

Other significant developments in 1967 that are NOT included in this film: the FCC established 911 as an emergency number. And 1967 was really the Bell System's heyday — the ESS switch had just started installations, and Dennis Ritchie, one of the inventors of UNIX, had just started working at Bell Labs.

Today, trains are tracked via RFID tags and GPS, and the microwave radio relays that carried broadcast television networks have been replaced by fixed-service satellites. And text, of course, instead of being transmitted via private line teletype, flows over the internet.

Footage courtesy of AT&T Archives and History Center, Warren, NJ