On leaving school, he worked for the Civil Service and had a successful career until an occasion when he lost his temper and had to leave. With the savings from his employment, he enrolled for a course at the Sorbonne, in Paris (apparently on a whim). However, he quickly ran out of money and began busking in the streets to support himself, playing the guitar and singing Leadbelly songs and Scottish folk songs. Some sources claim that he pretended to be a blind blues singer: a white stick enhanced the disguise.
He met the American folk musician Derroll Adams who found him a regular engagement, playing in a café, but Campbell also continued busking the streets. He made regular return trips to Britain in the 1950s, appearing at Alexis Korner's "Blues and Barrelhouse" club and other skiffle and folk music venues that were opening around the country. Back in Paris, a new generation of folk musicians, such as Davey Graham and Wizz Jones followed in his footsteps.
Campbell became involved in the folk music revival taking place in London and met Ewan MacColl, who was an influential figure in the folk movement. However, the two men disagreed on their approaches to folk music, with MacColl taking a very purist view that people should only sing music from their own regional background, whereas Campbell had an eclectic repertoire and sang whatever he liked, whether it was a Scottish Ballad, an English folksong or an American work song. A contemporary article in The Observer attempted to characterise the folk community into two camps: the "MacCollites" and the "Campbellites".
MacColl (Then married to Jean Newlove) had fallen in love with Peggy Seeger. In 1958, when Peggy Seeger's UK work permit ran out, Alex Campbell agreed to a marriage of convenience with her. On 24th January 1959 he married her in Paris. Seeger's USA passport had been withdrawn, and this marriage prevented deportation, and was, according to Seeger "a platonic relationship". Seeger has described the wedding ceremony as "hilarious": at the time she was seven months pregnant with Ewan MacColl's baby and the officiating priest lectured Campbell about his forthcoming lifetime commitment to "the poor girl whom he had got into so much trouble". The following day, Seeger returned to London and settled down with MacColl. Campbell himself settled down with his eventual wife, Patsy, and had two sons.
By 1961 Campbell was playing folk clubs in London, including Les Cousins. He toured Germany several times, and other parts of Europe. For several years he lived in Denmark, first in Skagen, and later in Tonder.
By the early 1980s he had throat cancer and could hardly speak. He died of tuberculosis in Denmark in January 1987.
In 1986, Rab Noakes wrote the song "Gently Does It" as a tribute to Campbell, contrasting the powerful presence Campbell had with the realities of his illness, and expressing a wish for him to slow down. The song includes the line "And a few years ago you'd been on this road so long", referencing Campbell's best known song.
The singer-songwriter Allan Taylor wrote, "Alex Campbell was the most important and influential folksinger of the folksong revival in Europe, admired, respected and loved by his fellow performers and his audiences. An outrageous, hard drinking, hard travelling, hard living man."
In his autobiography, the comedian Billy Connolly wrote of his admiration for Campbell.
Campbell is reputed to have recorded over 100 records, but was never commercially successful. He believed in recording quickly, rather than numerous re-takes to correct perceived imperfections in his performance. Backing musicians included Gerry Loughran, Royd Rivers, Dave Laibman and Ian McCann. Very few recordings are still in print.
Campbell's early recordings include quite a large share of American folk songs. Later his repertoire usually included Scots dialect songs, big ballads and erotic songs. He also sang Woody Guthrie, Bob Dylan and Tom Paxton songs and accompanied himself on guitar.
His 1967 album Alex Campbell and his Friends contains three songs with Sandy Denny taking the lead. They are the earliest available professional recordings by Denny.
His early recordings include contributions by Martin Carthy.
Allan Taylor issued "The Alex Campbell Tribute", a double CD.
"Been on the Road so Long" is currently his most easily-found album. It is the name of a song he wrote.