I came in with Halley's Comet in 1835. It is coming again next year, and I expect to go out with it. It will be the greatest disappointment of my life if I don't go out with Halley's Comet. The Almighty has said, no doubt: "Now here are these two unaccountable freaks; they came in together, they must go out together."
Halley's Comet is visible from Earth every 75 or 76 years. Twain was born shortly after the comet was visible in 1835. He made the above prediction in 1909. He was right: he died of a heart attack just as Halley's Comet was again visible on April 21, 1910. He was 74 years old. He was buried in Elmira, New York; the town is preparing a re-enactment of the funeral this weekend.
Much of Twain's life was marked by hardship. He lost substantial money through bad investments (printing technology, for one, and co-ownership in a failed publishing house, for another). For a time, he moved to Europe for its lower expenses and made his money as a lecturer. After about ten years, he returned to the United States — but not to his home in Hartford (today the Mark Twain House, open to the public) but to Redding, Connecticut. It was there, in the home named Stormfield, that he died a widower (his wife died the year before).
Shortly before his death, Twain donated the first books to what became the town's first public library. He asked it be named after his daughter, Jean, who had died a few months earlier. After Twain's death, businessman and philanthropist Andrew Carnegie helped fund it.