This section is from the book "The National Capitol. Its Architecture Art And History", by George C. Hazelton, Jr. Also available from Amazon: The National Capitol Its Architecture Art and History.
To the south of the so-called crypt, towards the wing of the House of Representatives, and opening from the main corridor, are the offices of the chief clerk of that body. The northeast room of this suite, in May, 1844, was the Washington terminus of Morse's telegraph, connecting the Capitol with the railroad depot in Pratt Street between Charles and Light Streets, Baltimore, over which was transmitted the first telegraphic message in the world's history. Miss Annie G. Ellsworth, daughter of Henry L. Ellsworth, then Commissioner of Patents, was honored with the choice of the words of the message, as she had been the first to announce to Morse the good news of the passage of the bill appropriating the money to build the wire. She chose': " What hath God wrought! "
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