I'm in the midst of reading a real page-turner, entitled, 'Mr. Lincoln's T-Mails.' It's written by Tom Wheeler and concerns our 16th president's real-time use of an emerging technology to help win the Civil War.
The Civil War is often called the first modern war because of multiple, simultaneous advancements in technology (everything from fast-moving trains to transport troops to the battlefield and ironclad ships to observations balloons and the smooth-bore rifle). In fact, it took generals on both sides most of the war to figure out that new technology had made most previous forms of military strategy basically obsolete. As a result, trench warfare was born.
The telegraph was another novel technology that had a profound, if almost totally, overlooked, impact on the war. It had been invented a few decades earlier but, aside from railroads, had not been adopted for any practical use. Then, along came Lincoln and the Civil War.
It didn't take the Great Emancipator long to build the White House's first telegraph office and have his cot moved in. He literally ran the war from that office. Lincoln would converse with his generals in near real-time (especially the less inept ones). He'd question their decisions, overrule the more absurd ones and literally bang out prototypical 'Dear John' telegraphs relieving incompetent field officers).