Formed in the summer of 1963, the group originally featured eponymous vocalist and harmonicist Paul Butterfield, guitarist Elvin Bishop, bassist Jerome Arnold, and drummer Sam Lay.

[1] The band added guitarist Mike Bloomfield and keyboardist Mark Naftalin before recording their self-titled debut album, which was released in October 1965.

[4]Eventually, Butterfield, on vocals and harmonica, and Bishop, accompanying him on guitar, were offered a regular gig at Big John's, a folk club in the Old Town district on Chicago's near North Side.

[4] With this booking, they persuaded bassist Jerome Arnold and drummer Sam Lay (both from Howlin' Wolf's touring band) to form a group with them in 1963.

[5] During their engagement at Big John's, Butterfield met and occasionally sat in with guitarist Mike Bloomfield, who was also playing at the club.

[5][6][7] Their first attempt to record an album, in December 1964, did not meet Rothchild's expectations, although an early version of "Born in Chicago", written by Gravenites, was included on the 1965 Elektra sampler Folksong '65 and created interest in the band.

These recordings also failed to satisfy Rothchild, but the group's appearances at the club brought them to the attention of the East Coast music community.

[10] In these recording sessions, Rothchild had assumed the role of group manager and used his folk contacts to secure the band more engagements outside of Chicago.

[11] Despite limited exposure on the first night and a dismissive introduction the following day by the folklorist and blues researcher Alan Lomax,[12][a] the band was able to attract an unusually large audience for a workshop performance.

Maria Muldaur, with her husband Geoff, who later toured and recorded with Butterfield, recalled the group's performance as stunning; it was the first time that many of the mostly folk-music fans had heard a high-powered electric blues combo.

With little rehearsal, Dylan performed a short, four-song set the next day with Bloomfield, Arnold, and Lay (along with Al Kooper and Barry Goldberg).

The 13-minute instrumental track "East-West" incorporates Indian raga influences and some of the earliest jazz-fusion and blues rock excursions, with extended solos by Butterfield and guitarists Mike Bloomfield and Elvin Bishop.

[18] Live versions of the song sometimes lasted nearly an hour, and performances at the San Francisco Fillmore Auditorium "were a huge influence on the city's jam bands".

[24] On its next album, In My Own Dream, released in 1968, the band continued to move away from its roots in Chicago blues towards a more soul-influenced, horn-based sound.

[13] The induction biography commented that "the Butterfield Band converted the country-blues purists and turned on the Fillmore generation to the pleasures of Muddy Waters, Howlin' Wolf, Little Walter, Willie Dixon and Elmore James".