Telephone

Alexander Graham Bell, USA, patent 174,465 of 1876. The most valuable single patent ever issued, filed hours before rival Gray.

Overview

Bell's patent application arrived February 14, 1876, hours before Elisha Gray's caveat for the same idea. The famous Mr Watson, come here call followed in March. Bell Telephone fought 600 lawsuits, beating Gray, Edison, and Western Union in the era's defining litigation. Theodore Vail built AT&T on the monopoly the patent seeded. Antonio Meucci's earlier work was recognized by Congress in 2002 but never overthrew it. The patent expired 1893, unleashing thousands of independent phone companies.