For a hot second there I was really excited to learn about historical telegram "data centers".
It's a capital T.
As a tangential niche-tourism shoutout: https://www.telcomhistory.org/ConnectionsSeattle.html
Granted, most of it is a bit newer than the heyday of telegrams, but there's a little bit of overlap.
You may have already read it, but portions of this sprawling (and very very good) essay by Neal Stephenson get into the topic: Mother Earth Mother Board - https://www.wired.com/1996/12/ffglass/
As a tangential niche-tourism shoutout: https://www.telcomhistory.org/ConnectionsSeattle.html
Granted, most of it is a bit newer than the heyday of telegrams, but there's a little bit of overlap.
You may have already read it, but portions of this sprawling (and very very good) essay by Neal Stephenson get into the topic: Mother Earth Mother Board - https://www.wired.com/1996/12/ffglass/