I recommend 'A Thread Across the Ocean: The Heroic Story of the Transatlantic Cable' by John Steele Gordon. [1]
From description,
"But in 1866, the Old and New Worlds were united by the successful laying of a cable across the Atlantic. John Steele Gordon's book chronicles this extraordinary achievement -- the brainchild of American businessman Cyrus Field and one of the greatest engineering feats of the nineteenth century. An epic struggle, it required a decade of effort, numerous failed attempts, millions of dollars in capital, a near disaster at sea, the overcoming of seemingly insurmountable technological problems, and uncommon physical, financial, and intellectual courage."
Also very enjoyable, and somewhat shorter (though still very long): 'Mother Earth Mother Board' [1], Neal Stephenson's essay on the laying of the FLAG cable, and related history.
That was such an amazing article. I still remember how long that story and how engaging it was. IIRC that issue of wired was like 20 pages thicker than the rest. Somewhere Stephenson talked about being grateful to Wired for not cutting it down to a 6k length. I still tell people the part about the library of Alexandria interconnect.
From description,
"But in 1866, the Old and New Worlds were united by the successful laying of a cable across the Atlantic. John Steele Gordon's book chronicles this extraordinary achievement -- the brainchild of American businessman Cyrus Field and one of the greatest engineering feats of the nineteenth century. An epic struggle, it required a decade of effort, numerous failed attempts, millions of dollars in capital, a near disaster at sea, the overcoming of seemingly insurmountable technological problems, and uncommon physical, financial, and intellectual courage."
[1] http://amzn.com/0060524464