Under what title was A Quick One released in the United States?

A Quick One was released in the United States under the title Happy Jack.

The Who's second studio album appeared in the UK as A Quick One in December 1966, but the American edition was retitled Happy Jack and released by Decca in April 1967. The change was connected to the song “Happy Jack,” which had become a successful single in the United States and gave the album a more recognizable American title.

The US edition also had a slightly altered track listing. “Happy Jack” replaced “Heat Wave,” helping connect the album to the band's first US top-40 hit. The single eventually reached No. 24 on the Billboard Hot 100, while the album peaked at No. 67 on the Billboard album chart.

This creates a frequent source of confusion: Happy Jack is not a separate Who studio album. It is the American title and configuration of A Quick One. The song itself was released as a single in the UK in December 1966 and in the US in March 1967. Later references may list both titles when discussing the same album.