Houston Anglos of all ages show advanced degrees of /u/-fronting. However, a close acoustic analysis of the fronted /u/ of younger and older Anglo Houstonians reveals two distinct types: a more monophthongal type, consistent with prior descriptions of fronted /u/ in the rural South, and a more diphthongal type, consistent with descriptions of /u/-fronting in non-Southern speakers. The two types differ in a number of fine temporal and spectral details. This provides an opportunity to test the hypothesis that the ongoing, supra-regional fronting of /u/ in North America represents an adoption of the older, Southern fronting pattern. Taken together with previous findings, the data presented in this paper argue against this view and for an analysis of /u/-fronting as independently innovated in the South and outside of the South. Judging by the data from Houston, today the traditional Southern type of fronting is being abandoned in the urban South in favor of the newer, regionally unmarked type. The paper explores the implications of these findings for sociophonetic studies of the urban South, speech perception studies, and the analysis of other cases of “shared” shifts.