In 1931, U.S. inventor Thomas Edison died.
The most prolific inventor in U.S. history, he registered 1,093 U.S. patents over the course of his lifetime.
Learn more at http://www.thomasedison.com/biography.html.
In 1954, Texas Instruments (TI) announced the first transistor radio, the Regency TR-1.
The Regency TR-1 was the first commercially sold transistor radio. Designed and manufactured in the U.S., over the course of the next year it sold over 100,000 units at a price of $49.99.