One of the most important questions surrounding the Northern Cities Shift (NCS) is its chronology: which vowel was the first to move, and how long ago did these movements happen? Based on a large-scale apparent-time study, Labov, Ash and Boberg (2006) posit that /ae/ ‘cat’ shifted first, followed by /o~ah/ ‘cot’. The authors note, however, that this ordering is tenuous. Authors such as Thomas (2001) propose the opposite ordering. The age of the NCS is also open for debate; Thomas (2001) presents evidence of its emergence prior to 1900 in Northern Ohio, although other accounts place it as a much more recent development. Data are drawn from the largest of the Northern Cities, Chicago. Apparent-time data for Chicago are neutral on the issue of ordering, as neither vowel shows ongoing change in the direction of the NCS. Real-time data are therefore crucial, and constitute the focus of this paper. Vowel tokens from six Chicagoans born between 1890 and 1920 are analyzed acoustically and their vowel plots are presented. These analyses suggest that /ah/ fronting predates /ae/ raising (but possibly not /ae/ tensing), as /ah/ fronting is present but /ae/ raising is absent in the very oldest speakers. In addition, /ah/ fronting has probably been present in Chicago since at least 1900, in accordance with Thomas (2001).