After seeing a demonstration of a typewriter in 1874, and despite a worldwide economic depression, Twain ran right out and bought one for the outrageous price of $125 [around $2,500 today]. Within a week, he was writing letters on it (in all capitals; it had no lowercase) about how he looked forward to giving it away: “IT is MOST TOO TEARING ON THE MIND,” he lamented. It’s sometimes hard to separate Twain’s real complaints from his curmudgeonly persona, so maybe he was exaggerating. But by 1875, he had given away his typewriter and decided instead to endorse new “fountain” pens for two companies …
Still, Twain did more than anyone to ensure the eventual triumph of typewriters over high-end pens. He submitted the first typewritten manuscript to a publisher, Life on the Mississippi, in 1883. (It was dictated to a secretary, not typed by Twain.) And when the Remington typewriter company asked him to endorse its machines … he declined with a crusty letter—which Remington turned around and printed anyway. Even the acknowledgement that Twain, probably the most popular person in America, owned one was endorsement enough.
From: Sam Kean; The Disappearing Spoon