Short answers, pulled from the story.
Gretsch was founded in 1883 by Friedrich Gretsch, a 27-year-old German immigrant, who opened a musical instrument shop at 128 Middleton Street in Brooklyn, New York. He made banjos, tambourines, and drums until his death in 1895 at the age of 39.
The Gretsch Filter'Tron is a humbucking pickup designed by American inventor Ray Butts in collaboration with guitarist Chet Atkins. It connects two single-coil pickups in series and out of phase to fight hum, and it was used on Gretsch guitars beginning in 1957. It may have been the first humbucker pickup, though that claim was lost to Gibson Guitars, who patented their design first.
Gretsch sales soared overnight after George Harrison played a Gretsch Country Gentleman during The Beatles' first appearance on the Ed Sullivan Show. Harrison had played Gretsch guitars since the band's early years.
By the mid-1950s Gretsch introduced the 6120 "Nashville," the 6128 Duo Jet chambered "solid body" played by Bo Diddley, the Country Club, and the White Falcon. Jimmie Webster also introduced the Gretsch Sparkle Jet in 1954 using sparkle finishes from Gretsch drums.
Gretsch was sold to Baldwin Pianos in 1967 after Fred Gretsch failed to find a suitable successor. In mid-1969 Baldwin moved manufacturing from Brooklyn to a plant in DeQueen, Arkansas, and in 1983 Baldwin's holding company entered bankruptcy with debt of over 9 billion dollars.
The Gretsch family regained leadership in 1985 when Fred W. Gretsch, great-grandson of Friedrich and nephew of Fred Gretsch Jr., became president. In late 2002 Gretsch reached an agreement giving Fender control over marketing, production, and distribution while the Gretsch family retained ownership.