1797 – Born on December 17th in Albany, New York. He was one of the first great American scientists after Benjamin Franklin. He aided Samuel F.B. Morse in the development of the telegraph and discovered several important principles of electricity, including self-induction, a phenomenon of primary importance in electronic circuitry.
1829 – While working with electromagnets at the Albany Academy (New York), he made important design improvements.
1831 – Although Michael Faraday is given credit for discovering electromagnetic induction—the process of converting magnetism into electricity—because he was the first to publish his results, Henry had observed the phenomenon a year earlier.
– Henry built and successfully operated, over a distance of one mile (1.6 kilometres), a telegraph of his own design.
1832 – He first noticed the principle of self-induction, three years after he devised and constructed the first electric motor.
– He became professor of natural philosophy at the College of New Jersey (later Princeton University).
1846 – Henry became the first secretary of the Smithsonian Institution, Washington, D.C., where he organized and supported a corps of volunteer weather observers.
1868 – He was the president of National Academy of Sciences.
1878 – He died on May 13th in Washington, D.C.
1893 – His name was given to the standard electrical unit of inductive resistance, the henry.