Making a long distance phone call in the early 20th century used to be a pain in the ass. You'd call an operator, who'd take down your info, tell you they'd call you back, then proceed to contact other operators along the route to build up a circuit. It would take minutes to build up the call. We take it for granted now of course. An important and often forgotten part of the mechanics of how we got from long distance calls and teletype to you Tweeting what you had for lunch is AT&T Long Lines. Stringing cable, then making microwave towers, from smaller network to smaller network enabled not only your long distance call, but television transmission, and other data services earlier than you might think. 40 years ago when ARPA hooked up the first nodes to what became the internet, Long Lines already saw what was coming down the road:

In the years ahead the business will be operating in a climate of rapid, radical change. To keep pace, communications will become increasingly versatile. There will be no artificial lines drawn between voice, visual and data communications. Instead, the customer will have at his disposal a universal, integrated communications service that is, a service that will enable him to talk, hear, see, write, examine documents or manipulate machines over great distances. The catalyst is the computer. Here's why: The complexity of modern life demands application of computers to help us solve our problems; -- computers demand communications; for human convenience, information must be made available in various forms. For instance, we may want to hear it or we may want to read it. We may also want to write back to the computer, to talk back-perhaps to draw pictures back. All this points to one universal network with the flexibility to handle all kinds of communications on demand. more »

For Long Lines the microwave tower won out over cable because it was cheaper and easier to maintain. The military used it for AUTOVON, creating specially nuclear strike hardened microwave stations and failover in case those pesky commies ever got agitated.

Ultimately, the thing that killed the Long Lines towers was the demand for bandwidth. A microwave link can only carry a small percentage of the capacity that a single fiberoptic strand can carry...and with the explosion of the Internet, it means that bandwidth is king. As AT&T replaced more and more of the old network with fiber, the towers became more valuable as towers that could be rededicated to cell sites...and so they have been given a new life. more »

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