The C.F. Martin company is America's longest-running instrument manufacturer, building great guitars since 1833. Martin perfected the dreadnaught guitar, named after a WWI battleship design, during the 1930s, and its loud, booming voice and rich tone influenced the development of many styles of modern music. From Mark Twain to Shania Twain, nearly every notable musician who has ever picked up a guitar has played a Martin. Many of the earliest-made Martins are still in use today.

   John Dopyera formed National in 1926, Dobro in 1929, and then merged the two companies in 1935 to start National-Dobro. As historian Tom Wheeler describes in American Guitars: "The history of National, Dobro and Valco is a labyrinthine saga so convoluted and rife with skeletons leaping out of closets that Dickens could have used it for a plot-twisting novel." National-Dobro manufactured high-quality resophonic instruments, electric lap steels, and electric guitars. Famous musicians like Memphis Minnie, Tampa Red, Sol Hoopii, and Stevie Ray Vaughan used National-Dobro guitars for a wide variety of musical styles such as blues, Hawaiian, country, jazz and rock 'n' roll. National guitars are acclaimed for their bluesy resophonic sound.

The Regal Musical Instrument Company, established 1908 in Chicago, produced thousands of student-grade and high-quality custom instruments. Musicians who wanted something really stylish had instruments built by the Regal custom shop. Regal was one of the world's largest instrument manufacturers during the 1930s through the 1950s.

 Swiss-born Adolph Rickenbacker and two partners formed the Rickenbacker Manufacturing Co., a metal stamping shop, in 1925. Rickenbacker, George Beauchamp, and others formed the Ro-Pat-In Corp. in 1931 to develop an electric guitar with a magnetic pickup. In 1953 Rickenbacker sold the company to F.C. Hall, the founder of an electronics company and the exclusive distributor of Fender products. In 1954, Hall expanded the guitar line with the introduction of a solidbody line and shifted Rickenbacker's emphasis away from Hawaiian steel guitars and towards Spanish-style electrics. In 1957, Roger Rossmeisl designed a new solidbody line for Rickenbacker, followed by the hollowbody Capri series in 1958. The Beatles popularized Rickenbacker guitars during the mid 1960s, helping the company become the dominant manufacturer of electric 12-strings.

  In 1932 Selmer of Paris began to produce a famous line of acoustic guitars in collaboration with musician-designer, Mario Maccafferi. By 1934, Selmer offered various guitar models suitable for jazz, Hawaiian, and classical music. The Gypsy king of swing, Django Reinhardt, endorsed and popularized Selmer guitars worldwide.

   Established in the late 1880s, the Oscar Schmidt company began producing guitars prior to WWI under the trade names of Stella and Sovereign. Stella is best known for their big-bodied 12-string guitars built between 1918 and 1938. The Stella 12-string was a moderately priced, well-made guitar favored by blues legends such as Blind Blake and Lead Belly.

  Charles Stromberg and Son, founded in 1905 in Boston, created some of the finest big-body archtop guitars of the 20th century. Their designs were innovative, attracting a clientele of well-known musicians such as Freddie Green and Hank Garland. Stromberg is best known for their top-of-the-line Deluxe and Master 400 models built during their golden period from 1940 to 1955. Fewer than 300 Stromberg guitars remain in existence.

 Washburn of Chicago began producing guitars, mandolins, zithers, and banjos near the end of the Civil War in 1864. By the end of the 19th century, Washburn became one of America's largest manufacturers, and their efforts had a profound impact on the steel-string guitar's development.