The Gaslight Anthem is an American rock band from New Brunswick, New Jersey, formed in 2006.
 The band consists of Brian Fallon (lead vocals, rhythm guitar), Alex Rosamilia (lead guitar, backing vocals), Alex Levine (bass guitar, backing vocals), and Benny Horowitz (drums, percussion, backing vocals).
James H. Mathis, Jr. (born August 1967), known as Jimbo Mathus, is an American singer-songwriter and guitarist, best known for his work with the swing revival band Squirrel Nut Zippers.
Andrew Wegman Bird (born July 11, 1973) is an American violinist, singer, and songwriter.
 He was a member of the bands Squirrel Nut Zippers and Bowl of Fire before pursuing a solo career.
 His main instrument is violin, but he also plays guitar and glockenspiel and is an expert whistler.
 He wrote and performed "The Whistling Caruso" for "The Muppets" movie and composed the score for the television series "Baskets".
 Andrew Bird currently lives in Los Angeles with his wife Katherine and their son Sam.
Thomas Edward Maxwell (born September 19, 1965) is an American songwriter, musician, vocalist, and writer.
 Most notably Maxwell is the former lead singer of the swing revival band Squirrel Nut Zippers.
 He wrote the single "Hell" from the 1996 certified platinum album "Hot".
Squirrel Nut Caramels (chocolate flavored) and Squirrel Nut Zippers (vanilla flavored) are chewy caramel candy mixed with peanuts.
Roasted Right is an EP by the swing revival band Squirrel Nut Zippers that was released in 1997.
 Unlike other albums by the Zippers, brass and woodwinds were replaced by guitars and the blues.
Bedlam Ballroom is the fifth studio album by the swing revival band Squirrel Nut Zippers, released in 2000.
 Most editions of the CD case have a lenticular cover.
 The cover artwork was created by artist Michael Doret.
Andrew Bird's Bowl of Fire was an American band fronted by musician Andrew Bird.
 After releasing his first solo album, "Music of Hair", Bird appeared on three albums by Squirrel Nut Zippers before becoming the bandleader for Andrew Bird's Bowl of Fire.
The Squirrel Nut Zippers is an American swing band formed in 1993 in Chapel Hill, North Carolina, by James "Jimbo" Mathus (vocals and guitar), Tom Maxwell (vocals and guitar), Katharine Whalen (vocals, banjo, ukulele), Chris Phillips (drums), Don Raleigh (bass guitar), and Ken Mosher.
Johnny Vomit & The Dry Heaves was a high school garage band that formed in mid-1980s Corinth, Mississippi, that featured future leaders of the Oblivians and Squirrel Nut Zippers, Jack Oblivian (né Yarber) and Jim Mathus.
 Under the names Johnny Goopa (Yarber on drums) and Bart Barf (Mathus on bass), they supported Johnny Vomit on two seven-inch records issued on Eric (né Friedl) Oblivian's Goner Records.

Question: Between the two American bands The Gaslight Anthem and Squirrel Nut Zippers, which band was formed earlier?
Answer: Squirrel Nut Zippers