📞 ⚡ 1876
Improvement in Telegraphy
U.S. Patent 174,465 · 1876
From the abstract
The method of, and apparatus for, transmitting vocal or other sounds telegraphically, as herein described, by causing electrical undulations, similar in form to the vibrations of the air accompanying the said vocal or other sound, substantially as set forth.
Note
The telephone, born as Claim 5. Bell filed on February 14, 1876 — the same day Elisha Gray filed a caveat for a similar device, and a few hours earlier. The dispute over who actually invented the variable-resistance transmitter has never fully closed. The patent itself ran 7,200 words. Within twenty years, AT&T was the most valuable corporation in the United States.