The National name goes way back to the early 1920s, when John and Rudy Dopyera started producing banjos in Southern California. Guitarist George Beauchamp approached the company with an idea on how to solve the lack of volume in the instruments of the Vaudevill Orchestra. His idea was to place an aluminum resonator in a guitar body to amplify the sound. With this idea, John Dopyera and four brothers formed National in 1925. This was the birth of possibly the greatest resonator guitar company.
National ran into financial hardship because of the Depression in the early 1930s. Louis Dopyera owned more than 50% of Dobro and bought out National in the early 1930s. He merged the two companies together and called it National-Dobro. In 1936, the company moved to Chicago, IL, where many companies were mass producing instruments (Kay, Harmony, etc.). Victor Smith, Al Frost, and Louis came together in 1943 to change the name of the company to VALCO (The initials of their three first names). Valco worked on war materials during WWII, and returned to start producing instruments afterwards.
Amplifiers first appeared in the 1930s and had a strikingly similar appearance to the acousic resonator instruments that they also produced. Some of these amps are known as "chicken feet." In the early 1940s, National began to produce amps with their National badge as the front grille. They also had some models with elaborate designs on the grille, such as the moon and stars.
After the war, Valco began producing amplifiers under the name National. Valco also produced amplifiers for other companies including Super, Oahu, Gretsch and Airline. Most of these amps were built between the late 1940s and the 1960s, and there is plenty of crossover in designs between all the brands.
In 1969 or 1970, Valco went bankrupt and the assests were auctioned off. The rights to the National trademark were bought by Strum & Drum in Chicago, IL. However, Strum & Drum didn't have a factory to produce National instruments, so they took the Norma brand guitars and amplifiers and applied the National logo to some of them. Naturally, this did not last long and all National-branded amplifiers were gone by the early 1970s. In 1988, Don Young and McGregor Gaines revived the National trademark under National Reso-Phonic Guitars but they focus strictly on resonator guitars. Early company history courtesy Bob Brozeman, The History And Artistry Of National Resonator Instruments.
Amplifiers previously produced in Chicago, IL under the company Valco between the late 1940s and early 1970s.