The recording of this album had an interesting process. Originally, studio sessions were planned for December 1964, but these were abandoned in favor of live recordings at New York's Café Au Go Go following the band's performance at the Newport Folk Festival. However, producer Rothchild was not satisfied with these recordings and decided a third attempt in the studio was necessary in September 1965. During these sessions, Mike Bloomfield stood out on guitars, while Elvin Bishop handled the rhythm riffs. Additionally, keyboardist Mark Naftalin joined, expanding the band to a sextet.
Among the most notable songs are "Born in Chicago", which opens the album with infectious energy, and "Mellow Down Easy", a Willie Dixon cover that showcases the band's versatility. "Shake Your Moneymaker" and "I Got My Mojo Working" are also key pieces reflecting the passion and authenticity of the blues. Each track offers a unique perspective on the Chicago style, with Butterfield's harmonica setting the tone and creating an atmosphere that evokes the true spirit of the genre. The music on this album is an unfiltered display, full of intensity and emotion, as expected from blues in its purest form.