Agreeing to a request by jail warden Winston Moore, King and his band performed for an audience of 2,117 prisoners, most of whom were young black men.

Live in Cook County Jail spent thirty-three weeks on the Billboard Top LPs chart, where it peaked at number twenty-five.

Rolling Stone ranked Live in Cook County Jail at number 499 on its list of the 500 Greatest Albums of All Time,[1] and in 2002, it was inducted into the Blues Foundation Hall of Fame.

"[3] King agreed, and politician Jerry Butler (former singer for the Impressions) helped to arrange a special free concert at the jail.

[3] The official then introduces King and his backing band, who begin to play a brief, fast tempo version of "Every Day I Have the Blues".

[3] The rest of the setlist in Live in Cook County Jail features slow blues tracks, with lyrical themes of separation and loneliness.

[9] Author Ulrich Adelt believes the setlist was chosen to elicit the feeling of nostalgia from the primarily black audience.

[10] The album cover features a photo of King playing a guitar lick against the background of blue prison walls and barred windows.

[3] The press surrounding the jail also gave King greater exposure to a white audience, to the point where a Chicago Tribune reporter felt the need to define blues music for the mainstream readership.

"[14] Billboard noted the prison setting brought upon new meanings to tracks like "Everyday I Have the Blues" and "Please Accept My Love", before ultimately writing: "King has done it again with this LP".

[15] John Landau of Rolling Stone wrote a more mixed review, where he criticized King's tendency to talk too much, as well as the audience's lack of enthusiasm.

Ulrich Adelt believes this is because Live at the Regal is routinely cited by critics as one of the greatest blues albums ever made.

[22] Reviewing in Christgau's Record Guide: Rock Albums of the Seventies (1981), Robert Christgau applauded King's "intensity" on renditions of older hits and said, "I prefer the horn arrangements on the Kent originals, but the unpredictable grit with which he snaps off the guitar parts makes up for any lost subtlety.

[1] Live in Cook County Jail's entry on the magazine's list of the greatest albums of all time states: "[King] won over the hostile prisoners with definitive versions of his blues standards and his crossover hit 'The Thrill Is Gone.