In 1960, he formed the Cumberland Three, which recorded three albums for Roulette. The following year, he joined the Kingston Trio, replacing Dave Guard, and stayed with them until 1967. His song "Daydream Believer" was a number one hit for the Monkees at the end of that year. Stewart traveled with Senator Robert Kennedy on his 1968 presidential campaign, an experience that affected him deeply. In 1969, he released his classic album California Bloodlines, the first of seven solo albums to reach the charts through 1980.

Stewart found his biggest commercial success with the Top Ten album Bombs Away Dream Babies and its single "Gold" in 1979. He released several of his albums and albums by others on his own Homecoming label starting in the 1980s. Airdream Believer appeared on Shanachie in 1995, followed by The American Folk Song Anthology on Delta in 1996. Rough Sketches and the live Bandera were released in 1997 and 1998, respectively, by Folk Era. Stewart signed with Appleseed Recordings in 2000, and his next three albums, Wires from the Bunker (2000), Havana (2003), and The Day the River Sang (2006), all appeared on the Appleseed imprint. Following Stewart's death on January 19, 2008, in San Diego, CA, Folk Era released a previously unheard live set (recorded at the Celebrity Theatre in Phoenix, AZ, on November 30, 1973) as Bite My Foot in 2009. ~ William Ruhlmann