Billie Calvin and Brenda Evans had been part of a group called The Delicates in the 1960s. They were introduced to Motown by singer Bobby Taylor, and, when The Delicates broke up in 1970, the two began providing background vocals for artists around Motown. They sung backing on the hits "Ain't No Mountain High Enough" for Diana Ross and "Still Water (Love)" for The Four Tops. Joe Harris had been part of a Detroit soul group called The Fabulous Peps. Formed in 1962, the group were renowned for their energetic stage performances, and they cut a handful of singles for various different labels before their dissolution in 1968. Harris also became a member of The Ohio Untouchables (later The Ohio Players). In 1970, Motown producer Norman Whitfield - partly as a response to criticism from Temptations fans that he was using the group as his personal plaything - put together Joe Harris, Billie Calvin and Brenda Evans to create his own recording act, The Undisputed Truth.

​The group's music and unusual costuming (large Afros and white makeup) typified the then-popular trend of "psychedelic soul" which Whitfield had inaugurated. A number of their singles became minor hits, and many of them were also songs for Whitfield's main act, The Temptations, among them 1971's "You Make Your Own Heaven and Hell Right Here on Earth" and "Papa Was A Rollin' Stone". Their single Top 40 hit in the United States was the ominous "Smiling Faces Sometimes," originally recorded by The Temptations, which hit #3 on the US Pop Charts in mid-1971.

Although they could never recreate the success of "Smiling Faces" they continued to make chart appearances throughout the early 1970s. They found some success with songs like "What It Is" (1972) and "Law of the Land" (1973) becoming modest hits on the US R&B Charts. In 1973, nevertheless, dissatisfied with the lack of major success, Brenda Evans left. She was briefly replaced by singer Diane Evans, but both she and Billie Calvin then left. Norman Whitfield subsequently took the opportunity to expand the group, and Joe Harris was joined by Virginia "Vee" McDonald, Tyrone "Big Ty" Douglas, Tyrone "Lil Ty" Barkley and Calvin "Dhaak" Stephenson. The latter four were all members of The Magic Tones, a Detroit soul group with similarities to George Clinton's pre-Funkadelic Parliament. Virginia McDonald (otherwise known as "Vee") is also the niece of Warren "Pete" Moore of the Famously Acclaimed Smokey Robinson and The Miracles.

​This new group scored several minor hits of their own, like "Help Yourself" and "I'm A Fool For You" (both 1974). "Help Yourself" became their second ever Top 20 R&B hit, peaking at #19, and reached #63 on the Hot 100, the highest position attained by any Undisputed Truth record for Motown besides their hit "Smiling Faces Sometimes". In 1975, the group's costuming and style changed, becoming even more unusual and Funkadelic-influenced. Their final albums for Motown, Cosmic Truth and Higher Than High (both 1975), yielded minor R&B chartings. Their 1975 song "Higher Than High" was featured most prominently in a TV advertisement for the 2015 film The Man From UNCLE.

​The Undisputed Truth, along with Rose Royce and Willie Hutch, followed Whitfield during his exodus from Motown to set up Whitfield Records in 1975. Both Virginia McDonald and Tyrone Douglas then left. The group went through many personnel changes thereafter, although original member Joe Harris remained with the group throughout. Taka Boom, Chaka Khan's sister, took over as female lead singer for 1976's Method To The Madness and Marcy Thomas replaced her for 1979's Smokin. Melvin Stewart and Lloyd Williams replaced Calvin Stevenson and Tyrone Barkley for the group's last album as well. Former member Billie Calvin later wrote songs for Whitfield's other group, Rose Royce, including the hit single "Wishing On A Star".

​The group had relatively little success at their new label, and faded into obscurity after two more albums. They did make their only ever entry into the UK Singles Chart in January 1977 (#43) with the disco single "You + Me = Love" from the album Method to the Madness.The song reached #48 on the American Billboard Hot 100, their second highest position ever on the chart. The Undisputed Truth nevertheless disbanded in the early 1980s following the collapse of Whitfield Records. Several former members became part of another Norman Whitfield-assembled group, Dream Machine, who had one album released, Dream Machine, and two singles, "Don't Walk Away" and "Shakedown", all in 1981. Vee McDonald recorded a solo album entitled Heavy Traffic Starring V (written and produced by Brianand Eddie Holland), which was released by Atlantic Records in 1986, with one single, "Jealousy", released that same year. Tyrone Barkley recorded a cover of The Del Royals' song "Man Of Value" in 1979; it is his only ever solo record and has since become an acclaimed Northern Soul favourite.

​In 1990, Joe Harris and Brenda Evans revived the group with singer Belita Woods, and recorded for Ian Levine's Motown revival label Motorcity Records. They recorded a new version of their 1973 song "Law of the Land", which was released as a 12" single (the group's last ever single) in 1991. Members Billie Calvin and Vee McDonald also made separate solo recordings for the same label, and all three feature on the A Tribute To Norman Whitfield album, a Motorcity compilation CD released in September 1996. McDonald recorded a song entitled "You're My Loveline" (co-written by former Motown lyricists Janie Bradford and Marilyn McLeod), which was released in the UK. Ian Levine has since described it as one of his "favourite ever Motorcity songs". Vee McDonald stills performs for Industry Parties and Clubs in the US and overseas, and has also performed for Michelle Obama, and Joe Harris continues to perform; Harris has most recently worked with the UK-based Stone Foundation band, and, along with Undisputed Truth member Calvin Stephenson, was inducted into the R&B Hall of Fame in 2015.

Founding member Billie Calvin died on June 23, 2007, at the age of 58, in Mureitta, California, USA, of heart disease. Tyrone "Lil Ty" Barkley died on February 14, 2017, at the age of 70, in Arizona.