Hi, Sol - here's a quote from www.allmusic.com:

One major misconception about the Brothers Four is that they were an attempt to emulate the Kingston Trio. Actually, Bob Flick (upright bass, baritone, bass), John Paine (guitar, baritone), Mike Kirkland (guitar, banjo, tenor), and Dick Foley (guitar, baritone) had met as undergraduates at the University of Washington in 1956 and began singing together in 1957, more than a year before the Kingston Trio made their first record. Folk music was booming at most liberal arts colleges in those days, and every campus seemed to have its share of trios and quartets, mostly drawn from the ranks of their fraternities. Flick, Paine, Kirkland, and Foley were all members of Phi Gamma Delta and aspired to careers in medicine, engineering, and diplomacy -- as amateur performers, however, they were good on their instruments and delighted campus audiences with their ability to harmonize on traditional tunes, novelty songs, and romantic ballads.

They turned professional completely by accident, as a result of a practical joke. A member of a rival fraternity arranged for a woman to telephone the group members, identifying herself as the secretary to the manager of a local Seattle venue, the Colony Club, and invite the quartet down to audition. When they got there, they discovered that there was no invitation or any audition scheduled, but since they were there anyway, the club manager asked them to do a couple of songs and ended up hiring them. The engagement lasted through most of 1958, and while they were often paid off only in beer, the experience was invaluable in that it allowed the group -- christened after their impromptu audition as the Brothers Four -- to pull its sound together as they never would have if they'd remained confined to occasional performances on campus.

Take a look at the rest of their biograhy at allmusic. It will tell you more than you'd ever want to know.
-Joe Offer-