The company was started in 1921 in Boston, Massachusetts by two brothers, Theodore and Milton Deutschmann, who wanted to provide equipment for the cutting-edge field of amateur, or "ham", radio. The store's name was taken from the name of the small structure that housed a ship's radio equipment at the time.
The company issued its first catalog in the early 1940s, and then entered the "high-fidelity" music market. In 1954, RadioShack began selling its own private-label product under the brand name "Realistic".
After expanding to nine stores plus an extensive mail-order business, the company fell on hard times in the 1960s. In 1963 it was bought by the Tandy Corporation, which started as a leather-goods corporation. Tandy eventually got rid of everything but electronics, and in May 2000, it dropped the Tandy name.
Tandy also operated a chain similar to Radio Shack in the UK during the 1970s and 1980s, but under its own name.
In 1977, RadioShack introduced the TRS-80, one of the first mass-produced personal computers. Affectionately known as the "trash-80", the machine became a big hit. In the late 1980s, RadioShack made the transition between its proprietary lines of 8-bit computers to its line of more or less IBM-compatible Tandy series of computers. However, shrinking margins and lack of economies of scale led RadioShack to exit the computer manufacturing market by the mid-1990s.
Until 2001, RadioShack was notorious for asking for the names and addresses of all customers who made even minor purchases so that they could be added to the RadioShack mailing list. This practice was discontinued reportedly after the CEO of the company made a purchase at a RadioShack store and realized how annoying this practice was.
RadioShack had another big hit with products designed to take advantage of the Family Radio Service, a short-range, walkie-talkie system. Since mid-1990s, RadioShack has attempted to move into the consumer small components markets, focusing on marketing wireless phones.