The musicians’ perfectionism required extra time to complete the track and it was taped only on 10 October, a long time after the planned deadline for studio recording.In an attempt to improve sales of the album, a shorter and heavily edited version of "River Deep - Mountain High" was released as single exclusively in the United States and Canada in February 1969, with "Listen, Learn, Read On" as the B-side.
Deep Purple's American record label aimed at a hippie audience, which was very influential in the US at the time, but the chart results of album and singles were not as high as expected.
This setback did not hinder the success of the three months long US tour, when the band played in many important venues and festivals and received positive feedback from audience and press.
Deep Purple were booked for a long tour in the United States, starting in October 1968, as a result of the unexpected success gathered in North America by their debut album Shades of Deep Purple, fronted by the hit single "Hush".
Executives at Tetragrammaton Records, Deep Purple's American label, thought that it would have been more profitable to have a new album to promote during the US tour, besides the already successful Shades of Deep Purple.
The band returned in England on 3 January 1969 and went straight into De Lane Lea Studios to record new songs.