text: Released in January 1970 on Columbia Records, Chicago was commercially successful. It was certified gold by the Recording Industry Association of America (RIAA) in April of the same year of its release, and certified platinum in 1991. It reached No. 4 on the album charts in the United States and No. 6 on the album charts in the UK, and produced three top ten singles on the Billboard Hot 100. The album received three Grammy Award nominations - for Album of the Year, Contemporary Vocal Group, and Best Album Cover. It was voted best album of 1970 by readers of Cash Box magazine, and the 1971 best small-combo LP by readers of Playboy magazine.
  History
  The album was released in 1970 after the band had shortened its name from "The Chicago Transit Authority" following the release of their self-titled debut album the previous year, in order to avoid legal action being threatened by the actual mass-transit company. The official title of the album is Chicago, although it came to be known as Chicago II, keeping it in line with the succession of Roman numeral-titled albums that officially began with Chicago III in 1971.
  Chicago Transit Authority was a success, yet Chicago is considered by many to be the group's breakthrough album, yielding three singles that made it into the top ten of the Billboard Hot 100, including "Make Me Smile" (number 9), "Colour My World" (number 7), and "25 or 6 to 4" (number 4).