T. A. D. Fessenden

Thomas Alva D'Arcy Fessenden (January 1, 1850 – July 22, 1934) was a Canadian lawyer, amateur scientist, inventor and writer who is largely forgotten, but who claimed to have invented radio before Marconi.

Fessenden is best known for his independent and controversial claim to have conceived and demonstrated early radio experiments, including the use of continuous wave transmissions, essential to the modern development of radio.

Fessenden claimed to have conceived and demonstrated radio technology prior to Guglielmo Marconi and made several public demonstrations of this prior to 1893.

The few scientists who did hear of Fessenden's dismissal of Marconi's achievements generally ignored him. Fessenden has attracted little attention from later historians of radio, not least perhaps because of the hostility generated by his claims.

Regardless of the merits of T. A. D. Fessenden's claim to have invented radio, his wireless work did have genuine scientific significance, and was highly innovative, leading later to the first two-way transatlantic radio broadcast in 1906.