We combine two approaches to gauge the achievements of the Mexican‐origin second generation: one the intergenerational progress between immigrant parents and children, the other the gap between the second generation and non‐Latino whites. We measure advancement of the Mexican‐origin second generation using a suite of census‐derived outcomes applied to immigrant parents in 1980 and grown children in 2005, as observed in California and Texas. Patterns of second‐generation upward mobility are similar in the two states, with important differences across outcome indicators. Assessments are less favorable for men than women, especially in Texas. We compare Mexican‐Americans to a non‐Latino white reference group, as do most assimilation studies. However, we separate the reference group into those born in the same state as the second generation and those who have migrated in. We find that selective in‐migration of more highly‐educated whites has raised the bar on some, not all, measures of attainment. This poses a challenge to studies of assimilation that do not compare grown‐children to their fellow natives of a state. Our model of greater temporal and regional specificity has broad applicability to studies guided by all theories of immigrant assimilation, integration and advancement.