 At the end of the sixties John Mayall was residing in Laurel Canyon, Los Angeles, California and had developed connections with local musicians, 
befriending Harvey Mandel and Larry Taylor, who had both just departed Canned Heat.Taylor had appeared on one track of Mayall's previous album, "Empty Rooms", the only studio recordings of his "Turning Point" band, and stayed on to replace Stephen Thompson (with whom he duetted on "To a Princess"); Mandel essentially replaced acoustic guitar specialist Jon Mark, and electric violinist Harris replaced saxophonist Johnny Almond.In the "USA Union" liner notes, Mayall noted that, after the Turning Point band broke up, he'd played a British music festival with an all-star lineup and then needed to form a new band swiftly when Polydor Records pressed him for a new album.