The Library of Congress is a treasure trove of historical information. The huge American Memory site is housed here, and you will see links to many other digital collections that are available online. Look for the link marked "Digital Collections" at the top of the page and EXPLORE!
The transistor radio made music easily portable. This is a Regency TR-1 transistor radio circa 1956. Notice the stylish gold dial.
(Courtesy of Steve Kushman and Gregory F. Maxwell; Transistor Radio, Wikimedia Commons)