Joseph Henry: Inventor of the Telegraph?

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  • Before becoming the first Secretary of the Smithsonian in 1846, Joseph Henry became known for his ground breaking research in electromagnetism and telegraphy. The author begins by describing earlier research in electricity and the telegraph and goes on to describe Henry's development, by 1831, of an electromagnet more powerful than any previously created. Henry went on to develop a telegraphic prototype that allowed for a bell to be rung at the other end of a mile-long copper wire. By 1835 he had developed precursors to all of the components essential to Morse's telegraph. Evidence for Henry's priority in developing the essential elements of the telegraph can be found in the notebooks of his students at Princeton, who described the experiments he demonstrated for them.
  • The second part of this article describes the protracted dispute between Joseph Henry and Samuel Morse over the origins of the telegraph. Although Henry had advised and encouraged Morse, a book published in 1845 by Alfred Vail, Morse's assistant, barely mentioned Henry's foundational work in electromagnetism. Henry was later subpoenaed to testify for defendants in several patent infringement cases brought by Morse. Henry credited himself with the scientific discoveries behind the telegraph, and as a result, Morse published a scathing attack of Henry. The author concludes that the two men "came to attach competing meanings and values to the work of scientists and inventors," with each believing their own work was most significant to the telegraph's invention.


  • Henry, Joseph 1797-1878
  • Morse, Samuel Finley Breese 1791-1872


Smithsonian History Bibliography


The author of this article was PhD candidate at Case Western Reserve University. The article was written for a website created in 1997 by the staff of the Joseph Henry Papers Project to mark the bicentennial of Henry's birth. It contains a photo of a surviving Henry electromagnet and several sketches.

Contained within

Joseph Henry, American Physicist (Website)

Contact information

Institutional History Division, Smithsonian Institution Archives, 600 Maryland Avenue, SW, Washington, D.C. 20024-2520,




  • Electric apparatus and appliances
  • Telegraph
  • Inventors
  • Scientific apparatus and instruments
  • Electromagnets
  • Electromagnet
  • Electromagnetism
  • Electromagnetic telegraph

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