Quote:
This "Dewey Defeats Truman" error in the Chicago Tribune resulted from many factors. Members of the Chicago Local 16 Typographical Union began a twenty-two-month strike on November 26, 1947. Inexperienced people had to type the front page, and rather than erasing typos or incorrect numbers, they would simply cross out mistakes with the x key on the typewriter. It was not uncommon to find mistakes, and in this famous issue, in the far right column, there were even five lines of upside-down type. This problem, as well as others, meant that the news had to go to press hours earlier than usual. That Tuesday in 1948, Maloney, the Tribune's managing editor, faced the problem of putting together his first post-election issue. Although the polls in the East, with a few exceptions in New Hampshire, had not reported their results, Arthur Sears Henning, the newspaper's Washington correspondent, made a projection of the winner in the national election. He had been wrong only once in twenty years about the elections and everyone on the 1948 staff of the Tribune agreed that Dewey would win.
Emphasis mine.